Offshore drilling and producing technology of total company
Kazakh-British Technical University
Faculty of oil and gas industry
Offshore drilling and producing technology of total company
Prepared by: student of 4th courseby: Professor
, 2013
Abstract
importance of the Offshore Province i n supplying a significant part of today's energy needs and an increasingly significant part of tomorrow's needs is unquestioned. The greatest uncertainty, however, is just how much of our future supply will come from the offshore areas and, from a total national viewpoint, what is the best way to develop and utilize the potential when balanced against all other alternatives .The evolution, present status and near term status of offshore drilling and production technology is reviewed and summarized. The application of this technology to the development of the petroleum potential of the continental margins (0 to 2500 meters) of the USA is discussed and illustrated . Some effects of hopefully accelerated offshore leasing are examined.course project includes 28 Figures, 2 patents, 5 articles.
Content
.New ways to monitor offshore environments
.Subsea intervention system for arctic and harsh weather
.Subsea Technologies for Tomorrow
.Improving Deepwater Recovery
.Improving Performance on Tomorrows Mature Fields
Introduction
purpose of this paper is to help provide the answers to at least a part of these questions by summarizing quantitatively the industry's existing capability to provide offshore drilling and producing systems. I n doing so it will be instructive to show the evolution of the various segments of offshore drilling and producing technology and to show how we got to where we are today.attempting to quantify the tremendous efforts , either in terms of manpower or dollars , I will show where technology stands as of today and where it will very likely be in the next four or five years more or less under existing momentum. I will also discuss how this technology i s related to the total potential of the continental margins of the U.S.A. The development of future technology will depend a great deal on the consistent progressive application of today's technology as well as the overall assessment of the rewards and benefits to be achieved by advancing the technology. Remember that technology is not only the acquisition and possession of scientific knowledge but more than that, it is the application of scientific knowledge. Let me bring t h i s point home. I am not aware of any field of scientific endeavor which has even possessed or purported to possess the "final" answer to a particular problem before attempting a solution . There have always been uncertainties and there always will be; but, the uncertainties diminish by orders of magnitude as soon as someone accomplishes the "feat". Then everyone jumps on the bandwagon and says,
"I knew it could be done!"and Gentlemen, the Petroleum Industry, and more particularly the offshore segment of t h a t industry, is no different in this regard from any other field of scientific endeavor. Categorical guarantees just are not in the cards. There al question and often times the most significant problem then is what is the best possible assessment of the realities of a potential course of action; in other words, "Which experts should one believe?" And let 's face it, this is no small task because the issues are complex and interwoven and the experts are numerous.
Integrated French energy giantis continuing to spread its wings as it focuses on liquefied natural gas (LNG), deep offshore developments, and heavy oil. The Company is seeking to maximize production from its existing fields, while at the same time boosting output from a raft of new projects it is bringing on stream over the next 5 years.has ambitious plans to grow oil and gas output by 2% per year and it is trying to strengthen its upstream arm through exploration, partnerships, and targeted asset deals. Total is the fifth-largest publicly traded integrated international oil and gas company in the world and is divided into three business segments − Upstream, Downstream, and Chemicals. It produces oil and gas in more than 30 countries, including Angola, Australia, Nigeria, Algeria, Canada, China, Russia, and Qatar.
1. New ways to monitor offshore environments
progress in techniques to monitor regular and planned exploration and production discharges offshore is expanding environmental management options for E&P companies. New water column and sediment measurement methods help make possible informed environmental management decisions. Such monitoring methods can be particularly important as E&P companies look to work in sensitive and previously unexplored environments that test the limits of conventional monitoring.some cases, tried and true methods have only limited applicability in deepwater operations and arctic projects. Furthermore, emissions from long-term, regular discharges are the subject of increased focus in terms of effects in the sea and in application of the best available treatment technologies.environmental monitoring can apply to permits and licenses, validation of numerical models, regulatory reporting, and technology selection. Nearly all the environmental management of an offshore installation relies in some way on the data from marine environmental surveys. For example, the initial state of the seas surrounding a development are monitored for baseline data and, following start-up, monitoring of the sediment and water column is performed periodically to help ensure the good environmental condition. Also, technology selection can be validated, as in the case of a platform in Norway where water treatment engineers used a fish biomarker survey to demonstrate the effectiveness of improved produced water treatment. Therefore, good, reliable data that represent temporal and spatial variation are needed to meet these and other environmental management needs. However, monitoring in the marine medium is challenging and limitations often restrict the amount of data available. More and more oil and gas developments are located offshore. Nevertheless, with easily accessible oil and gas provinces already having been explored, future developments will take place in increasingly harsh environments, such as the west of Shetlands North Sea, deeper and deeper offshore as well as ice-covered arctic waters. The current focus is on innovation in techniques and materials that enable human access to those ever-more difficult targets. A prime example is the Swimmer system for which Cybernetix, Statoil and Total initiated a feasibility study in 2007. After 18 months, Total decided to study further the Swimmer concept for the offshore Angolan specific application. Swimmer is a vehicle that performs inspection, maintenance and repair of subsea production systems with enhanced versatility and responsiveness. It is a hybrid system composed of an AUV (Autonomous Underwater Vehicle) and a ROV (Remotely Operated Vehicle). As such, it can perform pipeline inspections in AUV mode and light interventions on subsea equipment by deploying its own embedded ROV operated from topside production facilities. This innovative vehicle is designed to reduce operational risks as well as operating costs as it does not call anymore for a ROVsupport vessels. It is engineered to remain on the seafloor for up to three months at a time, without any need for maintenance. Swimmer is undergoing further development to meet tomorrows challenges - including deployment in arctic regions.
. Subsea intervention system for arctic and harsh weather
is a new hybrid AUV/ROV subsea intervention system for light inspection, maintenance, and repair (IMR) operations on subsea production systems (SPS). One prime advantage is that it can carry out IMR operations on its own, without a field support vessel. Once the Swimmer AUV shuttle is resting on its docking station, the ROV can be controlled fully from surface facilities via the production control umbilical. The Swimmers technical feasibility was shown in 2001 by full-scale sea trials. Since 2007, Total, Statoil, and Cybernetix have cooperated to develop a commercial version. Although the first application of this technology is earmarked for Totals Angola block 17 in late 2011, the partners are investigating use of the Swimmer system in offshore fields with extreme weather conditions. Swimmer not only can boost the flexibility and reduce the cost of operations for deep offshore fields, but also may become an enabling technology on ice covered arctic fields or in harsh environments such as the North Sea. The weather at these fields can prevent intervention vessels from operating for long periods, and is a personnel safety concern. In these conditions, the Swimmers ability to remain deployed subsea for several consecutive weeks is a key point for the operability and maintenance of such fields. For arctic regions, operations during ice formation and ice thickness may require an expensive icebreaker vessel. Drifting icebergs also threaten support vessels and production facilities. Sea state for some harsh environment areas may exceed Level 7 during parts of the year, making deployment and recovery of subsea intervention vehicles dangerous. Swimmer can be a tool to operate and or maintain subsea production assets when infrastructure is not reachable from the surface.CONCEPTprime advantage of swimmer is its capability to operate on its own, without a dedicated multiservice vessel (MSV). The AUV part of the hybrid vehicle, the so-called AUV shuttle, ideally is launched from surface production facilities or a vessel of opportunity, and programmed to navigate autonomously to a subsea docking station near the production equipment clusters. Once the Swimmer AUV shuttle is on its docking station, the Swimmer ROV can be remotely controlled from the surface via the field control umbilical. The operator has the hand over of the Swimmer ROV just like for a conventionally MSV-deployed ROV. In this configuration, the Swimmer ROV is powered by the FPSO (or from shore), and intervention is performed conventionally with real time data and video transmission. The Swimmer can remain deployed subsea for several consecutive weeks. Since the Swimmer performs all light IMR operations, the MSV can be dedicated to operations requiring handling of heavy equipment and modules. In this way, Swimmer introduces flexibility into the operations and reduces the overall opex.Swimmer concept was invented by Cybernetix in 1997. The feasibility of the concept was demonstrated successfully by Cybernetix and partners (IFREMER, the University of Liverpool) in October 2001 during full-scale sea trials. The Swimmer AUV prototype was programmed to autonomously reach and securely land onto a docking station at 100 m (328 ft) water depth to tap energy and communication for the Swimmer ROV. Following this demonstration, Cybernetix, with Statoil and Total, worked several cases to evaluate the economics of a Swimmer system for various fields. This work to a joint industry project (JIP) among the three partners to further study the technology. Phase 1 of the JIP showed the financial viability for future field developments, and recommended the extension of its scope of work to include pipeline survey and inspection.parallel, Cybernetix developed the Swimmer to a level of reliability required by the oil and gas industry. In particular, R&D efforts aimed at a robust and efficient docking algorithm, positioning and navigation systems, and subsea power and data transmissions. More recently, Total and Cybernetix are targeting the development and qualification of a Swimmer system for offshore Angola block 17.FEATURESSwimmer system is composed of both fixed and mobile assets. The fixed assets are part of the offshore field infrastructures and include the following:
▪Subsea docking stations
▪Subsea power and data cables embedded into the field control umbilicalconsoles integrated into the FPSO control room. The hybrid vehicle and the associated IMR tools form the mobile assets and include the following:
▪AUV shuttle
▪Light Work-ROV equipped with two manipulator arms
▪Work-ROV TMS integrated into the AUV shuttle
▪ROV tools for light IMR operations.Swimmer is designed to stay deployed subsea for up to three months. The current design depth is 1,500 m (4,921 ft) but can be extended to 3,000 m (9,842 ft). The AUV shuttle operating range is 20 km (12 mi) in the standard configuration, but can be extended to 50 km (31 mi), and cruising speed is up to 2 knots. Once docked, the ROV excursion around the docking station is in the 200 m (656 ft) range. The IMR tasks that can be performed by the Swimmer ROV include the following:
. Valve operation
. Cleaning
. Global, close, and detailed visual inspection
. Wall thickness measurement
. Cathodic protection measurement
. Support to electrical diagnosis and trouble shooting /fault finding
. Assistance to large module replacement
. Disconnection of lying leads
. Fluid and thermal leak detection
. Subsea sampling
. Replacement of small components
. Any other ROV operation requiring only the use of manipulators or manipulator carried tools. The Swimmer AUV can be programmed for field survey and pipeline inspection tasks such as the following:
. Field mapping
. Pipeline survey
. Pipeline close visual inspection
. Pipeline free span detection
. Pipeline localization
. Dropped objects detection
. Cathodic protection measurement.hybrid Swimmer vehicle combines ROV-borne IMR capabilities, suitable for maintaining SPS within tether range from the docking stations, with AUV-borne inspection capabilities for survey and inspection of subsea flow lines. Together, the scope of tasks covers the needs for all light IMR operations necessary to maintain a facility in production except replacement of large modules. The tools for IMR tasks on an SPS are generally small and can be embarked directly by the light Work-ROV, or alternatively put into storage compartments onboard the AUV shuttle.
Some tools do not yet satisfy the requirements of the Swimmer system, particularly on long deployments. These include:
1. Tools requiring calibration (e.g. torque tool) prior to use. These calibrations currently are done at the surface. Because the Swimmer system can remain subsea for an extended duration, and because the calibration preferably should be performed just before the operation, and suitable marine-grade devices will be needed.
. Seabed sampling is of interest for applications such as multiphase flow meter calibration, monitoring of oil-in-water and sand-in-water prior to reinjection, fiscal allocation, and reservoir monitoring for enhanced oil recovery programs.
. Hydraulic tools are not ideal for long duration subsea use, so all-electric equivalents should be developed (e.g. torque tool, brush, manipulator). Inspection of flow lines and cables, or general field survey, can be conducted from an AUV shuttle equipped with the guidance and data acquisition packages. The vehicle will autonomously follow its targeted path (e.g. a production flow line on the seabed), and record all relevant data on local storage devices for later analysis. After mission completion and return of the AUV to docking, data files are uploaded and the results analyzed offline. Because the operator is not in the loop during the survey, an AUV-based inspection is less reactive than with an ROV. However, its cost is lower and independent of the weather. Plus, the inspection may be repeated and modified for closer inspection if key points of interest were detected during the first survey. The DP-2 surface vessel is the main cost of conventional IMR. A key of the Swimmer is that it only requires a surface vessel for launch and recovery. The vessel can be released after the AUV has docked subsea. To further minimize MSV use and optimize opex, the Swimmer can remain operational subsea for up to three months at a time, without maintenance. This is achieved through careful hardware selection, and the implementation of multiple redundancies, fail-safe, and degraded mode layers throughout the system, such as redundant navigation sensors, communications, energy and electronics, fail-safe propulsion configurations, or redundant IMR tooling. Further extending its operating endurance to six months will result from two combined processes. Feedback from operating the first Swimmer systems on remote fields will help develop operating methods to minimizing failures. Collaboration with SPS manufacturers will help increase operating reliability, through careful design of the interfaces between the SPS and the Swimmer ROV. Secondly, iterative engineering analysis will lead to the selection of upgraded hardware, and the implementation of additional layers of redundancy and degraded functionalities.TO SURFACE CONDITIONSconditions, such as currents, waves and ice make deployment and recovery of an ROV uncertain, and risk harm to personnel and equipment, along with operating delays. Because the Swimmer is autonomous and hence untethered, launch and recovery may be done through a sequence of events decoupling the AUV from the ship. Launch may use a deployment ramp at the aft of the ship. The vehicle slides on the ramp and into the water, while the support vessel is cruising forward, preventing collision between the two. Alternately, the AUV may be deployed by the MSV to the seafloor while attached to its deck cradle -- essentially a light version of a standard docking station -- then the AUV can release from the cradle and navigate to the production field. The deck cradle is recovered by the MSV. Recovery of the Swimmer is initiated while it is on its docking station at the seabed. The surface vessel lowers the recovery apparatus attached to a crane or A-frame to the seafloor near the docking station. The Swimmer ROV captures the recovery apparatus, secures it to the AUV pad eyes on its top, and returns into the AUV. The AUV releases from the docking station and is hoisted to the surface as is done for standard ROVs. This eliminates most of the inherent risks of connecting a small marine vehicle to a larger one of a different dynamic behavior at sea. Furthermore, AUV recovery is not time critical, and may be postponed if necessary. In arctic areas, ocean surface formation of ice over subsea production fields can preclude operations, ultimately leading to IMR being interrupted or even worse, production facilities being shut down, until the ice recedes. Ice breakers may enable work, but with a significant price tag. Swimmer may be deployed by a surface vessel away from the area of ice formation, move autonomously to its docking station near the subsea facilities, and then operate regardless of surface conditions. The onboard inertial navigation system will guide the AUV towards the target docking station, assisted with acoustic positioning relative to the docking station when within a few kilometers range. When aintenance of the vehicle is needed, the vehicle will return autonomously to an icefree area for recovery., the Swimmer system can operate despite drifting icebergs. Apart from launch and recovery, all Swimmer operations are at 2 to 30 m (6.5 to 98 ft) above the seabed, and are remotely controlled by operators through a fast data link. The Swimmer AUV can navigate as far as 50 km (31 mi) from its starting point using onboard lithium batteries. This usually is sufficient to reach any destination across a single production field, between neighboring fields, or to an ice-covered field after being deployed at the limit of the ice layer. Yet higher ranges may be required, particularly if the vehicle must be fully autonomous from any surface support, and navigate on its own from the harbor to the production field, and back. Increased autonomy can come by adding battery packs, but with a weight and size penalty, and also by improving hydrodynamic efficiency. Research is under way to improve the autonomy of lithium batteries and will further increase the range of AUVs. An alternative for very long range (100 km [62 mi] and beyond) may be fuel cells. Already demonstrated on Jamstecs Urashima AUV, and Kongsbergs Hugin AUV, fuel cells may significantly increase energy storage onboard an AUV.operations (IO), or e-fields, rely on fast data-rate networks to connect offshore facilities to onshore bases for real-time monitor and control. This does not provide for local maintenance. Swimmer can provide remote IMR capability, provided its docking stations (across multiple subsea fields) are connected to the IO networks. IMR operations then can be done remotely from the onshore base.
3. Subsea Technologies for Tomorrow
the conquest of the ultra-deep offshore takes shape, subsea processing, electric power transmission and supply and the heating of long-distance transport lines will be the keys to success.Trace Heating of Effluent Transport Linestransport involves long distances, no insulation system, no matter how effective, can suffice to keep hydrocarbon temperatures above the threshold for hydrate formation. Hydrates are solid compounds liable to plug pipes. The only solution is to heat the multiphase lines that transport the production effluents.is in the vanguard of this field, with two technologies under development:trace heating: electric heating wires are wound between the two pipes of an insulated pipe-in-pipe line. The Group is the first to test this technology on a subsea gas pipeline linking the new Islay gas development in the British sector of the North Sea to the subsea gas gathering network that Total has already deployed over the area. As the conquest of the ultra-deep offshore takes shape, subsea processing, electric power transmission and supply and the heating of long-distance transport lines will be the keys to success.Trace Heating of Effluent Transport Linestransport involves long distances, no insulation system, no matter how effective, can suffice to keep hydrocarbon temperatures above the threshold for hydrate formation. Hydrates are solid compounds liable to plug pipes. The only solution is to heat the multiphase lines that transport the production effluents.
Total is in the vanguard of this field, with two technologies under development:trace heating: electric heating wires are wound between the two pipes of an insulated pipe-in-pipe line. The Group is the first to test this technology on a subsea gas pipeline linking the new Islay gas development in the British sector of the North Sea to the subsea gas gathering network that Total has already deployed over the area.fabric: the Energized Composite Solutions (ECS) technology capitalizes on the properties of a composite fabric coating to heat the lines. This "in-house" innovation is now undergoing a qualification program and has demonstrated a number of advantages over electric trace heating wires. These include the lighter weight and flexibility of the fabric that enable it to conform to any geometry, a more even distribution of heat, simplified repair, and low vulnerability to localized damage thanks to the many interconnections between the heating filaments.subsea processing - a term that refers to the full range of artificial lift and processing technologies carried out on the seafloor - new challenges such as difficult oils, long transport distances, "small" reservoirs and water depths in excess of 1,500 m have met their match.led the way into the strategic area of subsea processing with Pazflor, the first deep offshore development in the world to implement a subsea gas-liquids separation and subsea artificial lift of the liquids on a large scale. Three subsea separation units are installed under 800 m of water. Each one consists of a gravity gas-liquids separation module and two new-generation hybrid pumps. The pumps combine multiphase and centrifugal pumping technologies to boost the liquids up to the surface. These technological step-changes proved to be the key to cost-effective production of difficult oils: heavy (17 to 22 °API gravity), viscous (3 to 10 cP) and contained in low-pressure reservoirs.the qualification of the first High Boost multiphase pump (developed by Framo) completed in 2011, Total achieved a major new milestone in subsea pumping of fluids from a deep offshore reservoir, by reconciling a powerful pump (150 bar) and the ability to handle fluids containing a large (60%) volume of residual gas (Gas Volume Fraction, or GVF). Although the hybrid pumps developed for Pazflor were comparably powerful, they could not tolerate a high GVF. The Low Boost pumps on the market could tolerate a high GVF but were not sufficiently powerful (50 bar) for the Pazflor requirements.
Status report: Subsea pumps for all configurations
Thanks to its significant investments to develop a range of subsea pumping solutions, Total can avail itself of technologies suited to the varying needs of its portfolio of deep offshore assets for the next ten years:
for artificial lift of fluids right from the start of production in the case of heavy, viscous oils from reservoirs that are deeply buried or far from production hubs;
for maintaining plateau production on mature fields by supplying lift energy at the seafloor to maximize the recovery volume as the reservoirs decline.gas lift is also a critical technology for Total: gas compression on the seafloor becomes indispensable for transporting gas over long distances when reservoir pressure declines after several years of production. Total is involved in developing a field pilot for the Åsgard project operated by Statoil in the North Sea (Norway). The pilot is slated for installation in 2015.liquid separation is another decisive step toward maximizing the recovery on mature oil fields. The quantity of produced water inevitably increases over the fields life. The purpose of subsea liquid-liquid separation is to remove that water from the hydrocarbons (oil and gas) rather than bring it up to the FPSO. In line with this concept, Total is studying a highly innovative configuration that couples a liquid-liquid separation step with reinjection of the water into the reservoir.the future, the seawater injected into the reservoirs to enhance oil recovery will be treated on the seafloor as well. Total is working on SPRINGS (for Subsea Processing and Injection Gear for Seawater), the first seawater sulfate removal system designed for installation on the seafloor. With a treatment and injection capacity of 5,000 to 50,000 barrels of water per day, SPRINGS is designed for satellite oilfields located more than 10 kilometers from an FPSO vessel. It can also be deployed to optimize the production of existing fields without requiring any major revamp of the FPSO facilities. The nanofiltration membranes selected for this system have been qualified for a depth of 3,000 m, a first in the deep offshore industry. An industrial trial is tentatively planned for 2015.Toward All-Electricadvances in subsea processing and increasing distances from shore, hydraulic controls must be phased out in favor of electric ones. Indeed, electric controls offer a number of decisive advantages over hydraulic systems:
·greater reliability (hydraulics are the leading cause of failure of subsea equipment);
·more responsive, more precise control of facilities;
·better management of environmental impacts with the elimination of the risk of a hydraulic fluid leak;
·lower development costs with the elimination of the hydraulic lines in the umbilicals.years of research by Totals R&D teams (on wellheads and downhole safety valves) led to the qualification of these technologies for an initial deployment around 2013.
"With advances in subsea processing and increasing distances from shore, hydraulic controls must be phased out in favor of electric ones."
Subsea transmission and supply of electricity is another major enabler of subsea processing technologies. Totals research aims to define the electrical architectures for tomorrows developments, tailored according to water depth, tie-back distances and power requirements. The overarching goal of these studies is to achieve optimal reliability in order to streamline maintenance requirements and improve the availability of the facilities. Ultimately of course, the "subsea-to-shore" model for oil and gas developments far from any coastal infrastructure will best be served by locally-generated power. In 2011, Totals R&D undertook a program to identify the most viable solutions (such as wave energy or fuel cells) for a generating capacity of up to 20 MW.
4. Improving Deepwater Recovery
is highly committed to research on enhanced oil recovery and has launched the worlds first deep offshore polymer injection pilot.
Billions of Additional Barrels
At present, the recovery factor of conventional reserves averages around 32% of the oil in place. Improving on this performance is a strategic priority, for an increase of just 5% represents some 300 billion barrels of additional reserves - equivalent to the estimated future reserve discovery volume.technologies designed to raise recovery factors are collectively known as Enhanced Oil Recovery (EOR) technologies. Total has developed strong expertise in processes that involve injecting chemicals into the reservoirs. These have a dual objective:
·to optimize the efficiency of waterflood by injecting polymer-modified water with higher viscosity;
·to increase recovery by injecting surfactants and alkalis that displace more of the residual oil trapped in the reservoir matrix.
Focus - acting at different scales
Polymers are long chains of molecules that raise the viscosity of water as they "uncoil". By narrowing the gap between injection water viscosity and oil viscosity, these chemicals act at the macroscopic scale to improve the "piston" effect of the waterflood., surfactants and alkalis act at the microscopic scale. Surfactants are molecules with a hydrophilic head and a lipophilic tail: this dual affinity for water and oil is what displaces the oil fraction bypassed by conventional recovery techniques. Alkalis limit the adsorption of the surfactants by the reservoir rock, thus preventing surfactant loss as the waterflood advances through the deposit.
The Worlds First Viscosified Water Injection Pilotfactors make EOR more difficult to implement in the deep offshore context than in conventional reservoirs, namely:
·constraints related to the architecture of deepwater developments;
·the higher cost of field pilots.its tradition as a deepwater pioneer, Total is the first in the world to address the challenge of polymer-viscosified water flooding, on Dalia (Angola).in 2003, three years before the field came onstream, this project illustrates an important aspect of Totals EOR strategy: these technologies are not confined to mature oilfields, but have a role to play in new developments as well.
"Polymer-viscosifiedwaterflooding could raise recovery by 8% over 10 years."
Upon completion of injectivity tests of polymer-viscosified water in 2009, the field pilot was installed on three water injection wells on Camelia, one of the four Dalia reservoirs. A sampling well was drilled in 2011 behind the polymer-enhanced waterflood front. Over the course of 2012, samples check the presence and quality of the polymers, quantify the actual viscosity of the polymer-enhanced water and update the reservoir model. If results are on par with expectations, injections of polymer-viscosified water will be deployed to the entire Camelia reservoir and should result in approximately 8% additional recovery over ten years.
5. Improving Performance on Tomorrows Mature Fields
is the time to prepare for tomorrows aging deepwater facilities. Reinforcing their safety and reliability will depend on careful monitoring and the development of more effective inspection and repair solutions.2017, the Group will be operating nine deepwater FPSOs versus five today, along with 450 to 500 subsea wells. This change of scale will mean more subsea installations and more subsea processing - all involving increasingly sophisticated technologies.already on stream or still on the drawing board, these fields are located in inhospitable environments and are designed to produce for twenty years or more. With time, they will require more and more frequent interventions, bearing in mind that any failure will require costly resources and may result in detrimental production shutdowns.has developed top-notch expertise in in situ repairs, such as this intervention on a ruptured injection line (line WI 15) on the Girassol field.address these challenges, Total has already mobilized the IMR (Inspection, Maintenance, Repair) experts of its deep offshore teams. The stakes are enormous: their job is to develop tools to optimize the operability, reliability and safety of tomorrows mature fields.
Todays specialists already know how to monitor the integrity of infrastructure that is especially exposed to the inherent constraints of the deepwater environment (such as risers, mooring lines and export lines). However, the available data are still too fragmented. Tomorrows operator at the surface will need to have available a comprehensive vision of the subsea infrastructure and the capacity to intervene promptly if something goes wrong. With both of these goals in mind, Total teamed up with the French robotics engineering firm Cybernétix to develop an innovative IMR system.
The new concept is called SWIMMER (for Subsea Works Inspection and Maintenance with Minimum Environment ROV). It is based on an Autonomous Underwater Vehicle (AUV) which contains its own Remotely-Operated Vehicle (ROV), and is designed to spend up to three months on the sea floor. The AUV is programmed onboard the FPSO then "swims" under its own power to one of the docking stations installed at the bottom of the ocean. After it docks, it releases its ROV. The ROV itself is controlled by an operator at the surface, and can intervene anywhere within a 200-meter radius around the station.AUV has a range of 50 km. It is equipped with cameras, measurement instruments and a real-time interface to exchange data with the FPSO. The AUV can also inspect pipes and other equipment as it swims from one docking station to another.
SWIMMER embodies some key advances:
·in terms of responsiveness: uninterrupted presence on the seabed by the AUV for a period of three months improves surveillance of the installations and allows quicker intervention if necessary;
·in terms of economics: because it does not depend on a dedicated support vessel, the AUV can translate to a substantial reduction in operating costs.is already under way to develop second-generation SWIMMER and subsea communications systems to increase its range and applications.
Keeping a Close Watch on Pipes
The integrity of subsea pipelines and other equipment is the key to safe, reliable deepwater developments. Totals R&D organization is running a number of programs devoted to research on effective, economically viable solutions to these issues. Total now equips all its flexible risers with an innovative continuous monitoring system developed in partnership with Schlumberger. RACS (for Riser Annulus Condition Surveillance) checks the integrity of these strategic lines. By allowing real-time detection of anomalies in the riser annulus that could ultimately lead to a line rupture, this tool guarantees better safety.research program, the Emergency Pipe Repair System, directs its work more broadly at optimizing pipeline maintenance by identifying all risks of pipeline damage and taking an inventory of existing repair solutions.
Toward Hull Inspection by ROV
Every two and one-half years, a subsea inspection of the hulls of Totals fleet of FPSOs checks the integrity of the vessels, to guarantee the safety of the personnel on board, as well as of the production facilities. But the inspection operations present their own set of significant risks (e.g., waves, weather conditions) for the divers dispatched to intervene in water depths down to 30 meters. Moreover, the inspections mobilize considerable support resources (support vessels, hyperbaric chambers, etc.) for several weeks at a time.
Deploying an ROV controlled from the surface for hull inspections would offer some appealing advantages:
·It would improve the safety of operations by limiting diver intervention and therefore the risk of accidents;
·It would limit inspection time, since an ROV can operate for longer periods than a human diver, even in rough seas.evaluating the potential solutions, R&D opted in favor of a Crawler/HERO ROV developed by ECA and operated by DCNS. Compared with a conventional ROV, the Crawler/HERO robot is equipped with thrusters that enable it to "stick" directly on the surface of the FPSO hull. Totals R&D qualified this innovative solution in 2011. It is destined to be tested on one of Totals FPSO vessels in the future.
Optimizing Safety
A focus on the safety of people and operations has always been the foundation of Totals conquest of the deep offshore. For the Group, continually optimizing the technologies it develops to help operating teams foresee and prevent risks every step of the way is an absolute priority of its deepwater activities.
Managing the Risk of Well Blowout During Drilling
The drilling accident that took place in 2010 in the Gulf of Mexico provided a tragic reminder that there is no such thing as zero risk. This is particularly true in the deep offshore, where the industrys work involves increasing complexity and ever-deeper waters.analyses carried out by the Groups drilling experts indicated that complying with Totals safety standards would have averted that uncontrolled well blowout, which led to the explosion of a drilling rig. Although the probability of occurrence of this type of accident is low, Total has taken every measure to further enhance the safety of its drilling operations and learn the valuable lessons of this event. offshore environment intervention drillingterms of technology, Total has teamed up with partners in the industry to define new solutions that will enable a faster response in this type of situation. The goal is to develop equipment tailored to prompt interventions in the deepwater context, able to control and contain a well and cap a leak. In parallel, Total is working in-house to develop dedicated solutions for its own producing wells in the Gulf of Guinea.
Real-Time Monitoring of Geohazards
The sea bed is not without danger. Geohazards such as steep slopes, faults, shallow gas, landslides, mud volcanoes and gas hydrates can all cause instability, creating risks for subsea facilities, the people who run them and for the environment.date, surveys could assess these risks only during a finite window of time; first prior to the deployment of the installations, then at regular intervals. Acquisitions of such isolated data provide "snapshots" of the status of geohazards at one or more points in time. But there is no continuous monitoring of their status over time or in space.the complex geological environments of the Groups deepwater projects, managing these risks is crucial. Totals R&D rose to the challenge by introducing a technological world first called HORUS (for Hazards Observatory for Risk analysis by Underwater System). This subsea real-time geohazard monitoring station was patented in 2011.enables:
·continuous measurement of a set of physical characteristics of the water, seafloor and upper layer of subsea sediments. Measurements are performed using chemical sensors, a detector of gas bubbles escaping from the seafloor and various other types of probes (such as pressure, microseismicity and ground motion sensors);
·real-time analysis of the data gathered;
·semi-automatic triggering of warnings in the event of danger for personnel or facilities.is a major breakthrough that brings within grasp a real-time knowledge of changes in the key parameters of the subsea environment over the various phases of a fields life. This innovation is essential, given that alterations in pressure and temperature conditions, or vibrations generated by production operations, can sometimes cause soil instability. HORUS is a significant contributor to the safety of deepwater developments, and will soon be tested on one of Totals production sites.
OFFSHORE POTENTIAL AND TECHNOLOGY'S ROLE
Offshore Areas There has been a g r e a t deal of e f f o r t devoted to assessing the petroleum p o t e n t i a l of the c o n t i n e n t a l margins of the U.S. and the world. One of the more recent works is contained inMemoir 15 which was published by the 'American Association of Petroleum Geologists i n 1971 under the sponsorship of t h e N a t i o n a l Petroleum Council.c o n t i n e n t a l margins of the U.S., which include submerged lands from the s h o r e l i n e o u t to a water depth of 2500 meters, c o n s t i t u t e s an area of about 890,000,000 acres (1.4 m i l l i o n square miles). A s s t a t e d i n Memoir 15, some of t h i s area is known t o be non-prospective, although the report does not speculate on the s i z e of these non-prospective areas. Of the t o t a l 890,000,000 acres approximately 560,000,000 acres (63%) l i e on the c o n t i n e n t a l s h e l f (shorel i n e out to 200 m e t e r s ) . F i g u r e 49 d e p i c t s the t o t a l acreage and broadly how it is d i s t r i b u t e d . 421,000,000 acres (47%) l i e adjacent to the conterminous U .S .and the South Coast of Alaska. The remaining 469,000,000 acres (53%) a r e located north of the Alaskan peninsula. Also shown i s the amount of OCS and S t a t e acreage under lease compared t o the 239,000,000 acres located on the cont i n e n t a l s h e l f of the conterminous U.S. and the South Alaska coast. The approximate 5.0 m i l l i o n acres under l e a s e r e p r e s e n t about 2.0% of t h i s s h e l f area and about 112 of 1.0% of the t o t a l a r e a .50 d e p i c t s the d i s t r i b u t i o n of t h i s area by geologic and/or geographic provinces (see Reference 3). Those areas shown i n red a r e areas where ice is expected to be the s i g n i f i c a n t environmental c o n s t r a i n t . This includes the A r c t i c Margin, the Bering Sea S h e l f , B r i s t o l Bay and to some e x t e n t the Aleutian Shelves. Those areas shown i n blue a r e areas where winds, waves, currents , and/or earthquakes a r e expected to be the s i g n i f i c a n t environmental constraint .question we a r e a d d r e s s i n g o u r s e l v e s t o is, "How much of t h i s area is within reach of today's c a p a b i l i t y and how much is within reach of the expected s h o r t - t e r m e x t e n s i o n s of today's c a p a b i l i t y ? " L e t us consider f i r s t the blue a r e a s . Fixed platforms have been i n s t a l l e d i n the Gulf of Mexico i n up to 373 f e e t of water. Present designs f o r the North Sea where wind and wave conditions a r e expected t o be s i m i l a r to Gulf of Alaska conditions a r e approaching the 500-foot mark. In the Santa Barbara Channel platforms have been i n s t a l l e d in about 200 f e e t of water and a permit has been f i l e d f o r a platform i n s t a l l a t i o n i n approximately 850 f e e t of water. I n terms of extremes, assuming completion of the above p l a n s , platform f e a s i b i l i t y w i l l have been demonstrated i n 500 f e e t of water f o r North Sea type wind and wave environments and 850 f e e t of water i n an earthquake environment. I n terms of today's c a p a b i l i t y , I think it i s reasonable to say t h a t , with minor exception i f any, platform systems can be s u c c e s s f u l l y designed and i n s t a l l e d anywhere on the c o n t i n e n t a l s h e l f of the conterminous U.S. and the South Alaskan coast. A s shown on Figure 51, t h i s c a p a b i l i t y would account f o r a t o t a l of 239,000,000 acres o r b e t t e r than 114 . , < of the t o t a l a r e a . I n a d d i t i o n , some a d d i t i o n a l red area is within reach of t h i s same c a p a b i l i t y . I n Cook I n l e t , platforms have been i n s t a l l e d i n up t o 125 f e e t of w a t e r , e q u i v a l e n t to about 150 f e e t because of the a d d i t i o n a l depth caused by l a r g e t i d e s . These platforms have been designed f o r ice flows 3 to 4 f e e t thick c a r r i e d by c u r r e n t s of up to 10 t o 12 f e e t per second. Much a d d i t i o n a l work has been done regarding o t h e r types of s t r u c t u r e s which can be u t i l i z e d on the A r c t i c Margins such as the gravel f i l l e d i s l a n d i n s t a l l e d r e c e n t l y by Imperial O i l of Canada. Although somewhat more s p e c u l a t i v e , I think t h a t p l a t - form systems a r e probably f e a s i b l e i n up to 200 f e e t of water i n the B r i s t o l Bay area and t h e A l e u t i a n Shelves and r i g i d island-type s t r u c t u r e s a r e probably f e a s i b l e i n up t o 50 f e e t of water i n the remainder of t h e A r c t i c . A s shown i n Figure 51, t h i s a d d i t i o n a l a r e a r e p r e s e n t s some 35,000,000 acres and a t o t a l of 274,000,000 a c r e s w i t h i n reach of today's c a p a b i l i t y . Let us now look a t the s h o r t - t e r m e x t e n s i o n s t o e x i s t i n g c a p a b i l i t y . I n t h i s context, we mean t h a t over t h e n e x t four or five-year period given exi s t i n g R&D programs and o p e r a t i o n a l p l a n s, the a d d i t i o n a l c a p a b i l i t y t h a t w i l l ensue w i l l be a function of these c u r r e n t e f f o r t s . What w i l l happen beyond t h a t point is q u i t e another matter, however, since new programs w i l l be required and the success of e x i s t i n g programs w i l l have to be demonstrated. Figure 52 summarizes the c a p a b i l i t y p r o j e c t i o n of the system previously discussed. The c a p a b i l i t y t o d r i l l , t e s t and evaluate from a f l o a t i n g v e s s e l i n 1500 f e e t of water has been demonstrated. The SEDCO 445 has the c a p a b i l i t y t o d r i l l i n 2000 f e e t of water, and the design allows f o r extension to considerably g r e a t e r depths. Also, t h e r e a r e s e v e r a l e x i s t i n g r i g s i n a d d i t i o n to some of those under c o n s t r u c t i o n t h a t could be modified t o d r i l l i n up to 3000 f e e t of water i n one t o two years from now. It is, t h e r e f o r e , reasonable t h a t routine d r i l l i n g operations could be c a r r i e d out i n 3000 f e e t of water i n the '75 to '76 period. The water depth c a p a b i l i t y f o r wet t r e e completions is d i r e c t l y t i e d to the d r i l l i n g c a p a b i l i t y and c u r r e n t l y stands a t about 1500 f e e t . To date approximately 75 UWC's have been i n s t a l l e d i n water depths ranging from 50 t o 375 f e et . The technology required f o r the wet t r e e completions is n o t v e r y sens i t i v e to water depth and is, t h e r e f o r e , expected t o be extended i n t h e n e a r term to 3000 f e e t . The main c o n t r o l l i n g f a c t o r w i l l be the flowline connecting system and the hardware f o r i n s t a l l i n g t h e f l o w l i n e s , which w i l l be undergoing continual evolution as deepwater experience is gained. Current industry programs w i l l probably r e s u l t i n a d d i t i o n a l underwater completions over t h e n e x t few years and should provide the experience to develop a very r e l i a b l e and economically sounddeepwater wet t r e e completion system. The One-Atmosphere Chamber Wellhead System which was i n s t a l l e d by Lockheed Petroleum Services f o r S h e l l O i l Company recently i n its Main Pass 290 F i e l d has demonstrated the c a p a b i l i t y of t h i s completion system i n 375 f e e t of water. The diving capsule p a r t of t h i s system is r a t e d for 1200-foot water depth and t h i s , t h e r e f o r e , is considered the depth c a p a b i l i t y of t h i s system a t present. It is f o r e c a s t t h a t through design modification t h i s system's depth c a p a b i l i t y can be extended to 3000 f e e t . R&D work on underwater manifolding and production systems is c u r r e n t l y being c a r r i e d out and e i t h e r t h i s system or other systems such as f l o a t i n g production platforms could be a v a i l a b l e four to f i v e years from now given the r i g h t economic i n c e n t i v e s . Therefore, I think t h a t our short-term c a p a b i l i t y extension can provide the technology t o permit complete systems t o be i n s t a l l e d i n 3000 f e e t of water. Figure 53 i l l u s t r a t e s the a d d i t i o n a l e f f e c t of t h i s c a p a b i l i t y . On the margins of the conterminous U.S. plus the Alaska P a c i f i c Margin as i l l u s t r a t e d by the blue areas t h i s means the addition of about 103,000,000 acres. For the Alaskan portion (the red a r e a s ) , 32,000,000 acres is added. Regarding the Alaskan portion, it is recognized by t h e a u t h o r t h a t a g r e a t d e a l of e f f o r t is going i n t o Arctic Research t o develop the technology t o carry o u t e x p l o r a t i o n and production a c t i v i t y i n t h i s area. The recent announcement by Global Marine of the construction of an i c e breaking d r i l l s h i p is i n d i c a t i v e of the i n t e r e s t i n t h i s area. It is, therefore, poss i b l e t h a t the f i g u r e s quoted here f o r Alaska are conservative. However, an attempt has been made to include only t h a t a d d i t i o n a l area which has a reasonable c e r t a i n t y of being w i t h i n t h e c a p a b i l i t i e s purported. As an example of t h i s , only one-half of the B r i s t o l Bay area is included even though almost the e n t i r e area is i n l e s s than 600 f e e t of water. Although platforms and underwater systems i n combination could extend the basic platform depth c a p a b i l i t y (200 f e et ) the f a c t t h a t much of the area is 200 to 300 miles from shore w i l l cause s i g n i f i c a n t problems of access and t r a n s p o r t a t i o n . Figure 54 summarizes the t o t a l a r e a s w i t h i n reach of today's c a p a b i l i t y and t h a t a d d i t i o n a l area which is within reach of t h e s h o r t - t e r m extensions of today's c a p a b i l i t y . I n summary, approximately 274,000,000 acres (31% o f t h e t o t a l ) of t h e c o n t i n e n t a l margins of the U.S. a r e within reach of today's t e c h - nological c a p a b i l i t y and approximately 409,000,000 (46% of the t o t a l ) is within reach of our near-term c a p a b i l i t y . The r e a l question is what these 409,000,000 acres hold f o r us i n the way of petroleum r e s e r v e s . Mother Nature, i n the past, while yielding up bountif u l petroleum resources, has tended t o put very large portions i n r e l a t i v e l y few s p o t s , and no one w i l l r e a l l y know i f t h i s acreage contains s i g n i f i c a n t reserves u n t i l i t has been t e s t e d by the d r i l l . Our success or f a i l u r e i n so doing w i l l influence g r e a t l y the importance of and the r a t e a t which we pursue those portions of the c o n t i n e n t a l margins not presently within our c a p a b i l i t y . Therefore, we should pursue with a l l vigor and haste those areas t h a t are within our present- and near-term technological grasp and, a t the same time, we must continue to provide the necessary R&D programs t h a t w i l l i n s u r e t h e a b i l i t y to develop f e a s i b l e solutions f o r those areas t h a t a r e not presently within our c a p a b i l i t y . Some Implications of Accelerated Offshore Leasing Technological c a p a b i l i t y is one thing; however, there are several other important considerations t h a t must be examined. The economic aspect is one which looms i n a l l our minds a s perhaps even more formidable than technology and although not discussed i n t h i s paper, I c e r t a i n l y do not want to minimize that aspect. I would, however, like to discuss some of the considerations regarding industry response to hopefully accelerated offshore leasing. I n the report "U.S. Energy Outlook1' a preprint of which was released in December 1972 by the National Petroleum Council:,, several cases of accelerated domes t i c o i l and gas d r i l l i n g a c t i v i t y were examined (Chapter IV). The highest growth r a t e hypothesized i n that report was a 7.5 percent annual increase i n exploratory d r i l l i n g footage (labeled Case I ) . This increase in d r i l l i n g a c t i v i t y would achieve a level of a c t i v i t y i n 1985 about equal to the post World War I1 peak a c t i v i t y achieved i n 1955. Figure 55 i l l u s t r a t e s , in summary, the impact of t h i s case on the domestic energy and petroleum imports. The dotted l i n e s correspond to the same a c t i v i t y level as Case I but a lower finding r a t e . I think these two curves can be summarized as follows. By 1985, assuming the increased a c t i - v i t y becomes a r e a l i t y , the best we can do (high finding r a t e ) i s to achieve a level of dependence on foreign sources about equal to our c u r r e n t l e v e l . It i s possible, however, (low finding rate) that we would be able to only a r r e s t any further dependence beyond 1975. Although the NPC report does not give a completely detailed breakdown of the t o t a l offshore portion of the a c t i v i t y , enough d e t a i l i s given by region to estimate that which may be a t t r i b u t a b l e t o the offshore. Figure 56 was derived by applying the regional allocations for o i l and gas d r i l l i n g to the t o t a l o i l and gas d r i l l i n g f o r Case I. These r e s u l t s include only California, Gulf Coast and A t l a n t i c offshore (most of that which i s hypothesized), and for o i l d r i l l i n g , the regional allocations given for 'exploratory footage are assumed to apply to t o t a l o i l d r i l l i n g footage. Under these assumptions, the t o t a l offshore d r i l l i n g i n 1975 would be about 18M f e e t per year increasing to about 41M f e e t per year by 1985. Assuming that a l l of the exploratory footage (approximately 1/3 of the t o t a l footage) would be d r i l l e d from mobile platforms and the other 2/3 would be d r i l l e d from fixed platforms, Figure 57 shows the mobile r i g s which would be required to d r i l l this footage. Wells are assumed to be 10,000 f e e t and each well is assumed to take 45 days including t r a v e l , e t c . t o d r i l l. In 1975 approximately 74 mobile rigs would be required and this would increase by about 9 to 10 r i g s per year reaching a level of about 166 r i g s by 1985. For comparison, the existing number of mobile rigs (domestic) are shown a t the l e f t i n the figure. The annual increase of 9 to 10 r i g s per year represents about 20 to 25 percent of the present world r i g building capability of 40 to 50 r i g s per year. Figure 58 shows the number of 25 well fixed-platforms required again assuming 10,000-foot wells. S t e e l tonnages a r e also shown for 200,300, and 400-foot water depth s t r u c t u r e s . Although the water depth d i s t r i b u t i o n i s not known, i t i s reasonable that the tonnages would c e r t a i n l y f a l l somewhere i n t h i srange, perhaps averaging near the 300-foot l i n e . By 1985, the tonnage would increase to about 500,000 to 950,000 tons per year or a 3 to 6 fold increase over existing Gulf Coast capability of approximately 150,000 to 200,000 tons per year. This corresponds to an annual growth r a t e (over the next 12 years) of from 9.5 to 15 percent. Although no doubt additional f a c i l i t i e s would come into play during t h i s period (West Coast, East Coast, e t c .) , the r a t e of growth and the mobilization of additional f a c i l i t i e s would require s i g n i f i c a n t long range planning and a great amount of assurance to a t t r a c t investment c a p i t a l and trained manpower.two, examples above (mobile r i g s and fixed platforms) represent but a fraction of the t o t a l e f f o r t required to support a perhaps rather nominal increase i n present a c t i v i t y (NPC Case I ) . There are l i t e r a l l y hundreds of supporting i n d u s t r i e s who must be attuned to any escalating e f f o r t and who will also require firm assurance that a market for t h e i r goods and services w i l l be available.
Summary
the early beginning of offshore d r i l l i n g and production a c t i v i t i e s , the technology to provide the necessary safe and r e l i a b l e systems has very adequately kept pace with our economic needs. Existing technology related to a l l aspects of these a c t i v i t i e s has reached a high level of competence through the i n t e r - r e l a t e d e f f o r t s of research and development, engineering, and p r a c t i c a l experience. The technological "muscle", capable of working is almost one-half of the nation's continental margins, now stands ready to be flexed to help provide v i t a l domestic petroleum resources to meet our growing energy needs.
Acknowledgement
author acknowledges the many technical reports by those i n the industry, the-academic community and the government who have made valuable contributions to the development of offshore technology and the many others who have supplied the equipment and services to support t h i s new technology. The e f f o r t s of I . B . Boaz, C.A. S e l l a r s , and G .A. S t e r l i n g i n preparing t h i s paper are g r a t e f u l l y acknowledged, and the author thanks Shell O i l Company for permission to make t h i s presentation.
References
1. 1971, Future Petroleum Provinces of the United States - Their Geology and Potential: Memoir 15, Volumes I & 11, AAPG, Tulsa, Oklahoma.
. December 1972, U.S . Energy Outlook: Preprint National Petroleum Council.
. Nelson, T.W. and Burk, C .A . , 1966, Petroleum Resources of the Continental Margins of the United States .