bluuebunny/crossref_metadata_2025 huggingface dataset:
Smart. Leg : A New Method for Heavy Deck Offshore Installation
Authors: Labbé J.P. , Legras J.L. , Standing R.G.
Published: October 2008

A new shock less flotation method, called Smart-. Leg, developed by ETPM, is presented for the installation of a heavy deck on a jacket in open sea using a conventional cargo barge and specific recoverable devices, The details and advantages of the method are discussed. The paper also summarizes the dynamic analyses carried out to assess the efficiency of the specific devices; one is mounted on the barge and designed to stabilize it inside the jacket and another one is fitted inside the deck legs and designed to land the deck smoothly on the jacket.

The advantages of the integrated deck concept for large offshore platforms have been widely publicized. However, so far, the installation of heavy decks in open sea using the floatation method has been limited either by the shocks to be absorbed during the mating operation or by the difficulty of maintaining the barge steady inside the jacket.

With the new method and associated equipment, mating shocks are virtually eliminated and the barge is smoothly and steadily maintained within the jacket. The system allows, a deck weighing up to 20,000 tons to& installed in a 2m / 10s heading swell, The results of the numerical analyses performed provide crucial data on motions and forces for the design of the new flotation method. The prototype tests (scale 1/4) give precise indications about Smart-Leg parameters and the tank tests (scale 1/40) enable validation of the numerical analysis.

Introduction

Few methods permit the installation of heavy integrated decks offshore particularly in long swell seas where the ergo barge movements have high amplitudes. Smart-. Leg is the floatation method that can install the heaviest integrated deck in open sea using only a conventional cargo barge and specific reusable equipment.

With Smart- Leg and the accompanying stabilization devicesSmart- Fin, and Smart-Fender shocks during mating and barge immobilization are eliminated, As a result, a deck weighing more than 20,000 t ean be installed in a 2rn/10s swell. The principle used by Smart-. Leg devices is that whatever the size and mass of a heaving, surging or swaying body, its kinetic energy is zero when its velocity is zero. Smart-Leg, Smart-Fin and Smart-Fender are based on a jacking device that um detect the outward zero speed of the ram and maintain that ram position. A non-return valve located between the high pressure chamber (ram side) and the low pressure accumulator of the jacking device seines both purposes,

Another advantage of the Smart-Leg system is that the reverse operation (deck removal) is possible using the same principle and therefore without any shock.

The principle of Smart-Leg has already been validated inshore during the installation of the main girders of the Prince Edward Island bridge. Each of the 5 girders already installed weighs more that 7000 t.

The first Smart-Leg equipment will be ready for an offshore installation early 1997 and able to install a deck in the weight range 3500 t to 6000 t,
Seastar: Subsea Cluster Manifold System Design and Installation
Authors: Mason Paul T. , Upchurch John L.
Published: October 2008

The SeaStar CIuster Manifold system was engineered as A low cost alternative to larger and more expensive completion template designs. Utilizing field-proven equipment and installation techniques, it was the first of its kind to be installed in the Gulf of Mexico. The Cluster Manifold system allows the connection of flowlines from adjacent satellite wells and numerous in field flowlines consisting of export, service, and methanol lines. With new technological advances, and a variety of flowline connection systems on the market today, deep water completions are being used with increasing frequency. Subsea operations are becoming more routine and installation times are being reduced. The SeaStar system was successfully installed in Garden Banks Block 70/71 in the Gulf of Mexico during the first quarter of 1995. Currently two (2) 4'x2') 10,000 psi lay-away trees are installed and connected to the manifold. Production is being processed at a Marathon platform in Vermilion Block 386B approximately 13.5 miles away from the subsea installation.

Introduction

The SeaStar development is located in Garden Banks Block 70/7 1 approximately 120 miles south of Cameron, Louisiana. The water depth at this location is 750 ft. The subsea equipment consists of a 4-slot manifold system, two 4'x2' 10,000 psi lay-away trees with retrievable choke inserts, electro-hydraulic (E/H) control system, E/H Umbilical, Umbilical Termination Assembly (UTA), flexible well jumpers with collet connector, hard pipe spool pieces with C&X connectors for the 6' export flowline and 2' service jumper, and four (4) 2' methanol lines. The manifold is used to commings gas production from up to four wells and deliver the production gas via dual 6' subsea pipelines to a host platform processing facility 13,5 miles distant in Vermilion Block 386B. An existing subsea sales gas pipeline system then transports the processed gas to shore.

Economic and feasibility studies were conducted from March to August of 1993 to determine the optimum development scenario. The subsea tie-back to an existing facility was chosen over a new-build, fixed platform, due to its low cost and optimum feasibility. From August to December of 1993, predevelopment engineering studies were conducted to determine overall project costs. In early January 1994, the %&tar project was kicked off.

When the project was kicked off in January 1994, three (3) wells had already been drilled, two in GB 70 and one in GB 71. The wells were drilled using a spacer template which provided a 16 R spacing between the three wells. The northern most well (GB 70 #2) was suspended following testing and will not be completed. Fig-1 shows the as-built field layout of the Manifold system, 6' and 2' hard pipe spool pieces, three well locations, two 6' flowline skids, 2' service line skid, four 2' methanol pipe lines, and the E/H umbilical.
Engineering Appraisal Of Pipeline Flotation During Backfilling
Authors: Cathle D.N. , Machin J.B. , Overy R.F.
Published: October 2008

A case history of two 8' flowlines which were trenched and backfilled in the Northern North Sea is presented. The majority of the trench was cut in sands and soft clay overlying the uneven surface of a hard clay, The trenching operation as successful with the pipe set at the required depth, but the post-backfill survey revealed long sections of both lines exposed at the surface. The problems were resolved by retrenching, dumping a screed of rock and then repeating the backfilling operation. Post-installation engineering work was performed to establish the likely cause of the pipe uplift. A pipe flotation hypothesis was advanced and this paper concentrates on the work performed on this scenario. The conclusions reached were that during backfilling the mixing of the tine sand, silt, clay and shells produced a very high void ratio material that behaved as a slurry for long enough to allow the pipe to progressively uplift as the backfill plough passed, Soils to be trenched and backfilled should be investigated very carefully, not only for trench ability and in-service behaviour, but also for short term behaviour during backfilling and consolidation.

Introduction

A case history is described to further the state-of-the-art in the design of backfilling operations. A mechanism by which pipeline uplift during backfilling can occur and how it can be anticipated is described. Under contract to Shell Expro, Coflexip Stena Offshore (CSO) successfully installed the Cormorant Alpha to Pelican flowlines. Following pipe laying, the trenching operation was successfully completed using CSO'S multi-pass plough and the lines were lowered to the required depth of approximately 1.5 m. Backfilling was then performed using a backfill plough (Figure 1). However, the post back filling survey revealed long sections of both lines lying on the surface of the backfill, The problems were resolved by retrenching, dumping a screed of rock and then repeating the backfilling operation. Post-installation engineering work was performed to establish the likely cause of the pipe uplift. This paper provides a summary of the case history, an explanation of the probable uplift mechanism, and the lessons learned from the project.

Soil Conditions

Pre-trenching data. Cone penetrometer testing (CPT) was performed along the route. Some sampling at the Pelican end of the route was used to assist the interpretation of the CPT'S which used the standard correlations.' The sampling programme revealed interbedded loose sand and soft clay overlying stiff clay. Based on the site investigation, three soil units were distinguished :Unit 1 Very loose to medium dense SAND (varying between 0.3 and 0.7 m thick)Unit 2 Very soft CLAY (varying between 0.0 and greater than 2 m thick) sometimes with sand layersUnit 3 Firm to hard CLAY with gravel and sand layers
New Mooring Chain Designs
Authors: Cafiada Luis , Vicinay Javier , Sanz Alejandro , Lopez Eduardo
Published: October 2008

The present work introduces the readers to the developments the high technology offshore chain industry has carried out m recent yearn, m an effort to offer products that meet the needs of petroleum exploration and production. In Ibis manner the industry can continue to regard chain as a fundamental element in its moorings system. whether for projects with a 25 year life, or projects at depths of over 1,000 meters, or ]n such severe environments as those faced In the Sub-Artic

Data is presented on STUDLESS CHAIN and VGW or Variable Geometry and Weight chain. These will allow engineers designers to forget the needs for chains to be circumscribed to rigid guidelines of geometry or dimensions, Instead they can design rnooring sysems specific for the particular situations they face. No longer shall chain have to meet geometric standardization derived from the middle of the 19th century while meeting the requirements of the 2nd half of the 20th century.

1- INTRODUCTION

For its use in mooring systems for floating platforms, chain has been adapted over the years to meet the increasingly Innovative requirements of the offshore industry

Until recently. chain had always been supplied with studs. a design going back to the second half of the 19th century. probably begun In the year 1858 by the Committee Of Lloyd's Register (l). AI the time this was an impressive.. technological leap forward for the development of Mooring Systems for the shipbuilding industry

When the offshore oil industry started in the 1960s. the chain m current use was designed for ships, As offshore Installations began requiring higher specifications, the standards for offshore chain began to differ born those of marine chain.

Major milestones in this process were:1970s- Developments of the API-2F standard. with the Introduction of ORQ). as a new concept and chain quality (2)1980s- Further progress on the ORQ concept, with the development and standardization of Grade 4 chains based primarily on DNV - CN 2.6, of July 1985 (3, and ABS "Guide to Certification of Offshore Mooring Chain 1985 (4).First half of the 90s. - Break with the old design concept of stud link chain, with the introduction of STUDLESS CHAIN, now being standardized with DNV's August 1.995revislon of CN 2.6, which will come into force on l" July 1996, (5)Second half of the 90$, - Dimension standards begin change with the introduction of the new VGW chain or VARIABLE GEOMETRY AND DIMENSION CHAINS, designed to meet specific project requirements, as in the case of STLIDLESS chain

The development of new chains during the 1990s made it necessary to consider whether chain standards should continue In their present form, i.e., with clear unequivocal Quality Assurance specifications, mechanical properties and geometric constants The purpose of this article is to examine the current application of STUDLESS CHAIN and VGW CHAlN. and whether 01 not DIMENSION STANDARDS should be changed.
Through Tubing Window Milling - A Cost Effective Method of Casing Exit
Authors: Blizzard B. , Carter T. , Roberts J.
Published: October 2008

Through tubing operations currently provide oilfield operators with an attractive method for significantly enhancing production at a relatively low cost. ?This paper will present a newly developed and innovative system for initiating a production casing sidetrack below the production tubing. The system uses coiled tubing technology and blends the special techniques of both drilling and window milling operations using coiled tubing. Development details emphasized will be the overall system design, performance criteria and equipment evaluation.

Introduction

Sidetracking through tubing represents a special technical challenge. The casing exit equipment must first pass through the relative small confines of production tubing and then provide a platform within the larger production casing belowfor casing exit operations. This transition from a small to large tubular represents a significant obstacle to the functionality of the system. To function properly, the platform must support the loads imposed during the casing exit activity (milling) as well as provide guidance to subsequent reentry operations. Of course, as always, the technique and associated equipment must be as cost effective as possible in order to fully benefit from the through tubing aspects of this type of well intervention.

Various types of through tubing sidetrack methods have been developed for meeting this challenge. To date, the largest number of exits performed utilize a cement plug. Bent downhole motor housings and bent subs are conveyed with coiled tubing and drive a mill to create a casing exit using the cement for support. 1A variation of that method consists of a cement plug with a pilot hole in which a conventional whipstock is placed. Figures 1 and 2 illustrate these methods. Both of these techniques require cement to be placed and therefore are not optimal solutions. True optimization and benefit of through tubing techniques lie in the ability to achieve an exitquickly,with a minimum number of trips in the hole,with minimal risk to the formation,that provides for repeated reentryand a quick return to production.

Clearly, a system that does not require cement and does not completely block access to the casing below the platform would be an optimal situation. The only practical manner of providing such a system is to utilize robust component hardware that expands to bridge the distance across the casing bore. Through tubing whipstock systems provide the best method to date to achieve this bridging This technology is in its early stages and only a few whipstock systems are available to the industry.

The following text serves to both describe a new system that has been recently developed and to document what has been determined to be the critical design issues relating to this type of casing exit technology.
The 'Marine Quality Kit'; a Tool to Monitor Accelerations, Velocities and Motions in Arbitrary Locations on Floating Objects
Authors: Bos A.J. , van Hoonaard A.
Published: October 2008

During design stages of offshore operations the maximum allowable values for accelerations, velocities and motions are calculated. These values are translated into environmental conditions, such as: maximum wave height and maximum wind speed. On site operational progress is based on the comparisons between the actual (or forecasted) and the maximum allowable environmental conditions. Hydrographic and Marine Consultants BV (HMC) and MARIN developed a tool, to monitor real time the values as mentioned under (1) on arbitrary locations on floating objects.

Thus factors used in (2) and (3) are becoming tangible. Safe operation will be maintained by a known Safety Factor. The online information and trend analyses make the MQK to reduce down time in marine operations.

Introduction and objective

Decision making during offshore projects is often based on entities deducted from calculated parameters from the design stage of the project, In 1994 HMC and MARIN decided to develop a portable tool to monitor the accelerations, velocities and motions in arbitrary locations on floating objects. The tool needed to be easy to install and easy to use.

Primarily monitoring had two purposes:To monitor real time the values of above-mentioned parameters.To collect statistical data of above-mentioned parameters. Data and results were to be integrated in a Decision Support System to achieve a tool to compare real time values against design criteria and to adjust operational decisions to enhance safety and to reduce downtime, Shipboard operations can be supported directly. Data and results can be saved for later analyses. Because this encompasses the Quality Control during marine operations the system was named the MARINE QUALITY KIT (MQK). The MQK would consist of a sensorbox and a laptop computer (figure 2).

During the study for the MQK an inventory was made regarding the available hardware and software. I hardware components for the sensorbox were available in different types and brands, Software for integration of the monitoring system and analyses and forecasting software with the possibilities of data processing, presentation and data storage was not available and was to be developed.

In this paper a resume of the possible fields of application is given together with a table with the bandwidths for accelerations and periods for the six degrees of freedom. This will be followed by a list of sensors that maybe used in the sensor box. A hardware build-up of the sensor is presented as well, followed by a calculation procedure and a software and user-interface description, Finally an evaluation of a pilot project with a cutter dredger is given followed by the conclusions.
The Harding Move: Opening Up New Horizons
Authors: Feith Jurgina , Hoekstra J.P.
Published: October 2008

During July-September 1995 Dockwise successfully completed the unique load-out, transport and discharge operation of the 22,870 ton BP-Harding PDQ-unit from Korea to the North Sea via the Suez Canal on board [he self-propelled heavy-lift vessel "Transsbelf'. This unique loading operation involved skidding the 22,870 [on platform via the side of the vessel over four skidbeams. Special solutions had to be found for stability, load spreading, mooring, ballasting and manoeuvring. Due to the 2.6 meter grillage height, special procedures were required for maintaining stability during discharge by float-off. The experience gained in this project may lead to a further extension of load-out and transport possibilities on a worldwide scale, utilizing the presently available fleet of heavy-lift vessels.

Introduction

For the development of the Harding Field, located in the Central North Sea, BP Exploration Ltd ordered a Technic Geoproduction designed TPG 500 from Hyundai Heavy Industries (HHI) in Ulsan, Korea. The TPG 500 is a fully integrated Production Drilling and Quarters (PDQ), three leg, jack-up platform. The legs were specifically designed for installation above a preinstalled concrete Gravity Base Tank. The design was such that the legs could not be fully retracted leaving a protrusion of 2.2 meters from the hull, which was to have a major impact on the transport concept, The platform had a transport weight of 22,870 tons and measured 88.72 meters in length, 111.75 meters in width and had a total leg length of 121.5 meters (Fig. 1).

Due to the fact that the unit was built on a normal construction quay rather than inside a dry dock, loading took place by a skid-on method via the side of the 'Transshelf'. To facilitate this the vessel was fitted with four transverse skidbeams on deck, connected to the skidbeams on the quay. The actual loading was carried out using a skid-shoe and pulling system, the resulting elevation above the vessel's deck amounted to 2.6 m.

Furthermore, in order to optimize the initial stability, sponsoons were fitted on each side. The load transfer onto the vessel was carefully monitored and compensated with the vessel's own high capacity ballasting system.

Unique events come with unique problems, which needed to be solved by a multi-discipline team, Skidding 22,870 tons via the side of a vessel would be a unique operation in vessel or barge load-outs. In April 1993 a successful cooperation started with all parties involved (BPX, TPG, HHI and Doekwise, which resulted in the 4-track skidding concept to facilitate the transverse load-out.

Skidshoe Arrangement

A hydraulic-jack-skidshoe system had to be designed to linearize the loads on the skidbeams to avoid overstressing of the vessel and the PDQ. A special low profile skidbeam was designed to stay within the limits of the grillage height which had grown to 2.6 meters.
Liuhua 11-1 Development-FPS Flexible Risers
Authors: Kirkham Benjamin F. , Hughes John D. , Bo Zhang , Hardin Donald J.
Published: October 2008

The FPS riser system represented a significant challenge for the team developing the Liuhua 11-1 Field. The use of downhole electric submersible pumps was instrumental to the exploitation of the hydrocarbon reserves, with an electricpower cable riser required for each well. Regardless of the assumed life expectancy of the cables in a dynamic environment, the system had to provide for their easy recent and replacement. Including the four hydraulic control bundles and a 2-in. flexible pipe service riser, a minimum of 25 risers will be suspended from the PI%. The riser array features a support buoy and clump weight for each riser. The FPS provides the means to install and recover the risers without a support vessel. The design objectives met by the riser system included survival of the 100-yr typhoon and 100-yr soliton events. Teamwork and innovative thinking from the project team contributed to successful installation of the riser may and initial deployment of the risers.

Riser System Overview

An overview of the development of the Liuhua Field by Amoco Orient Petroleum Company (AOPC), and partners, China Offshore Oil Nanhai East Corporation and Kerr- McGee China Petroleum Ltd. is presented in OTC 8172 (Ref. 1). The subsea production system overview is in OTC 8175 (Ref. 2). The FPS riser army provides at least 25 permanent, direct links between the FPS, Nanhai Tiao Zhan, whose conversion is detailed in OTC 8187 (Ref. 3), and the subsea equipment to support field production operations. None of the FPS risers carry produced fluids, which instead are routed directly to the FPSO tanker, Nanhai sheng Li, whose conversion is detailed in OTC 8188 (Ref. 4), through the two infield production and one test pipelines. The FPS riser army consists of three types of riser, as follows:Electrical in-water power cable (IWPC) risers, one for each of the 20 to 24 planned subsea wells, used to supply power to downhole electric submersible pumps (ESPS) the use of which is detailed in OTC 8176 (Ref. 5)Four hydraulic umbilical risers, one for each branch of wells, which terminate to hydraulic distribution bases (HDBs) on the subsea manifold and which control valves, deliver treating chemicals, and convey pressure signalsOne 2-in. inside diameter flexible pipe service riser used for hydrostatic testing, batch treating, and flushing the subsea manifold system

Many configurations were evaluated for suspending the riser may from the FPS. The preferred configuration uses subsea buoys arranged in a pattern offset from the subsea wells under the FPS (Fig 1). Each riser is suspended from one of two specially built porches located under the FPS main deck and is draped in a catenary from thereto the top of a subsea buoy (Fig. 2). From the subsea buoys, the IWPCS lead to, and terminate at, the subsea well tree caps. The hydraulic umbilical risers assume a similar conjuration, but terminate at the HDBs on the central manifold.
Design Considerations in the First UKCS High Pressure/ High Temperature Field
Authors: Brubaker J.P.
Published: October 2008

The Erskine field will be the first high pressure / high temperature (HPHT) field- developed in the North Sea. Erskine presents a number of technical challenges requiring safe, cost effective, and innovative design solutions Specifically, a safe Normally Unattended installation (NUI) is required, severe wax and corrosion problems have to be dealt with, a process module has to be installed in a minimal space, and foremost, HPHT safety concerns have to be addressed. The Erskine design achieves (1) a planned NW visit frequency of four to six weeks, (2) transportation and processing of very waxy fluids through cold (40° F) North Sea waters, (3) transportation of hot (300° F) corrosive fluids in a carbon steel pipeline, (4) over-pressure protection without the use of relief valves, and (5) a compact, minimum area processing module added 10 an existing host platform..

Introduction

The Erskine Field is a gas condensate field located in 296 feet of water within the United Kingdom Continental Shelf (UKCS) 150 miles east of Aberdeen. Recoverable resumes are estimated at 335 BCF of gas and 75 MMBBL of liquids. The field design production rates are 117 MMSCFD and 30,650 BOPD. The field was sanctioned and approved in April 1995 and plateau gas sales will commence 1 October 1997. The field development configuration is shown in Fig. 1 and consists of a NUl tied back to a Host Platform (Lomond Platform) 19 miles distant via a 16' nominal bore multiphase pipeline. A dedicated processing module will be installed on Lomond. The module will receive the multiphase fluids and separate, process, meter, and export the dried gas and condensate into the existing CATS gas system and the Forties Pipeline System respectively. The design of the Erskine facilities had to overcome a number of technical challenges.The Erskine HPHT reservoirs have initial bottom hole conditions of 14,000 psia and 350°F, wellhead shut-in pressure (WHSIP) of 10,600 psia, and flowing surface temperatures of 300° F.Production fluids contain up to 33 ppmv H2S. 5.5 mole % CO2ard 90,000 ppm Cl'.Field reserves are considered marginal for North Sea development.Condensate contains approximately 10 wt. % wax forming compounds.Host platform is located 19 miles distant.The host platform space for module footprint is limited 10 a 30 ft by 61 ft area.

Technical solutions to these field challenges have taken the following forms:

Minimum Attendance Installation.

In an effort to reduce personnel risks to as low as practical, all aspects of the Erskine platform have been designed to minimise manned intervention. Many NUI'S require one or more weekly interventions. The Erskine platform has a maximum planned visit frequency of once every four to six weeks.
Prevention of Severe Slugging in the Dunbar 16' Multiphase Pipeline
Authors: Courbot A.
Published: October 2008

The occurrence of the severe slugging phenomenon in multiphase pipelines can cause serious and troublesome operational problems within the receiving process facilities.

This paper describes: the pipeline operability studies on the Dunbar to Always multiphase pipeline regarding riser-induced severe slugging; the control scheme selected to prevent this phenomenon; and the subsequent operating experience. The pipeline operability studies involving dynamic simulations concluded that riser-induced severe slugging could occur over a wide range of production rates, in particular when the ElIon gas is unavailable.

The challenge for TOTAL was to develop an operating strategy and a control scheme in order to eliminate severe slugging and operate the pipeline without significant process upset.

An automatic control scheme was selected which offered a cost effective solution and ensured the safety of the existing process installations. Its originality was that it was based on a Riser Base Pressure Control.

Since the initial start-up in December 1994, this selected scheme has proven to be successful and has enabled the pipeline operations in the riser-induced severe slugging region to be carried out without any difficulty.

Introduction

The Dunbar field is situated in the UK sector of the northern North Sea, approximately 22 km to the South of Alwyn North field which has been operated since the end of 1987 (Fig. 1 and Fig. 2).

The recent development of the Dunbar field and its satellite ElIon comprises a production platform linked to the Alwyn North platform by a 16' multiphase pipeline (Fig. 3). The gas from El- Ion (Subsea wells) and the oil and gas from Dunbar are co-mingled and the overall well-fluid production is routed without separation to the Alwyn North processing and treatment facilities.

The Dunbar 16' Multiphase Pipeline has been designed to export the Dunbar and Ellen production to Alwyn North (NAB platform) at a maximum flow of 49000 BOPD and 7.9 MMSCMD. Over a wide range of production rates, in particular when the ElIon gas is unavailable, the pipeline operation is in an unstable region where riser- induced severe occurs.

The purpose of this document is :. to give a short description of the flow regimes predicted in the DUNBAR 16' Multiphase Pipeline and in particular of the severe slugging phenomenon.to present the operating strategy and the control system developed by TOTAL in order to prevent severe slugging and to operate the pipeline without occurrence of significant process upsets.and to give a feed-back of the pipeline operation at low flow rates

1. Flow regimes and severe slugging

The pipeline profile of the Dunbar 16' pipeline is represented in Fig. 4. The flow regime map for this pipeline operated at a NAB riser-base pressure of 74 is given in Fig. 5 This map was based on the results of dynamic simulations performed with the OLGA pipeline software.
In-Situ Polymerisation of an Inflatable Composite Sleeve to Reline Damaged Tubing and Shut-Off Perforation
Authors: Saltel J.L. , Leighton J. , Faure A. , Baaijens T.
Published: October 2008

Finding an effective solution to seal-off perforations. whether it be to reduce gas flow, reduce water cut. or to modify injection profiles. has long been a subject of concern. Several solutions for through tubing shut-off have been tried with a varying level of success

After 3 years of testing a new technology has been developed to manufacture a composite sleeve using elastomers. fibres and thermo-setting resins. The sleeve is run-in on electric wireline, inflated to push the composite against the inside of the casing, then heated to polymerise the resins. The running equipment is extracted to leave a pressure resistant inner lining in place. There is little diameter loss, leaning access to the well below, and opening up applications for tubing repair. Following successful field trials commercial operations have begun.

Introduction

Composite material are generally composed of reinforced fibres such as glass, carbon or steel bedded in a matrix. The fibres generally provide the majority of the strength and the matrix serves to maintain them in place and to transfer the stresses to them. The matrices used may be soft or rigid :flexible matrices can be used for deformable products When this is the case, the matrix is mainly an elastomer. It has almost nothing to do with the mechanical strength, but acts solely as a binder for the fibres (protection, seal), Among other applications, some examples are various types of seals, car tires, membranes, etc.Rigid matrices form products that are not deformable and provide a degree of strength to the composite material. especially in the crosswise direction of the fibres.

Fibreglass boats, fibreglass easing, are common examples. Very generally. a product is used either in a flexible and hence deformable state or else in a rigid and hence unreformable state.

Using the deformability properties of a composite material with a thermo setting matrix in its unpolymerised state, while preserving its great mechanical properties obtained after polymerisation has several advantages. The crosslinking of the resin occurs directly at the place where the end product will be used. and not dring manufacturing as it is usually the ease. This means the composite can be shaped to the desired form in the wel1.and opens up a multitude of potential applications. For example composite easing can be manufactured in lengths of up to 1,000 meters and enable mono-diameter well to be designed with considerable savings. The first available application of this technology is the Patch-Flex, designed for remedial applications. A short composite tube manufactured with thermosetting resins is run on electric wireline opposite the zone to be treated. It is inflated and polymerised to leave a self supporting cylindrical lining3 (Fig. 1).

Operating Principles

Product and Equipment. Run and set in electric wireline (Fig. 1 and 2) The Patch-Flex itself is composed of two principle parts (Fig. 3).
Coiled Tubing Drilling: Real Time MWD With Dedicated Powers to the BHA
Authors: Leismer Dwayne , Williams Brock , Pursell John
Published: October 2008

This paper describes and analyzes the development and ongoing field trials of a Real Time MWD Coiled Tubing Drilling System. The new system holds great promise for advancingthe state of coiled tubing drilling for certain applications. The system is designed for through-tubing, short radius re-entry and drilling highly deviated wells as horizontal laterals to a geologic target with minimum wellbore tortuosity. Currently, 4- 1/2' production tubing is the smallest re-entry candidate. Real time MWD and Bottom Hole Assembly (BHA) control is achieved by the use of a combination hydraulic and electric umbilical internal to the coiled tubing (CT), allowing continuous data collection and selective surface control of the BHA components, This communication line allows orientation in 10' increments (or less) while drilling, applies weight-on-bit and operates a reusable circulating valve. In addition, the umbilical provides real-time monitoring of weight-on-bit, circulating pressures of the drilling fluid internal and external to the BHA, dedicated hydraulic system bottom hole pressure, downhole temperature and survey data from logging equipment.

Introduction

In. June of 1992, Cameo Products & Services formed a coiled tubing drilling team that consisted of engineering representives from Reed Tool Company, Hycalog. Cameo Coiled Tubing Services and Cameo Products & Services. The team's objective was to investigate the technical and economic viability of drilling with CT. Invitations were extended to experts and consultants with experience in slim-hole and CT drilling to address the team on existing and potential problems. The major technical difficulties identified were:CT bucklingpipe fatiguelack of real-time dataweigh t-on-bitreactive torquedependable emergency release from the BHAability to drill under balanced

Key to solving these technical difficulties is the ability to provide hydraulic and electric power to the BHA via an umbilical installed in the CT, The umbilical allowed the development of hydraulically and electronically powered down hole tools and instrumentation that comprise the BHA. Purpose built surface equipment designed specifically for the BHA was developed to provide surface power and selective controls.

After conceptual drawings of the BHA were completed, Cameo and BP Exploration (Alaska) began a development project for specific application at Prudhoe Bay, where CT drillingtechnology is considered to be a very valuable tool. Many of the existing wells at Prudhoe Bay could potentially benefit if replaced with horizontal completions. CT drilling offers the potential of achieving horizontal sidetracks without pulling the existing tubing. This offers a significant cost advantage over conventional sidetracks.
Waxy Crude Oil Production in the South China Sea
Authors: Low W.R. , Gerber E.J. , Simek L.A. , Brown John
Published: October 2008

The Philips petroleum international Corporation Asia (PPICA) XI Jiang field Development Project Is a unique project resulting m the production of a waxy crude oil. The crude oil IS produced on two platforms feeding a final production unit located on an ITS() (floating Production, Storage and (XT-loading) vessel located between the platforms (see Figure 1)

Introduction and Background

The Xi jiang field is located approximately 80 miles southeast of I long Kong m the South China Sea It was discovered by Phillips Petroleum Co and China National Offshore Oil Company (CNO(IC) in early 1983 after initial seismic tests were pa-forward The first wells were spudded for blocks XJ24- 3 and XJ30-2 on Nov 29, 1984 and Jan. 15, 1984, respectively:.

The two platforms arc located in blocks XJ24-3 and XJ30-2 m approximately 330 feet of water These two facilities arc separated by about 45,000 feet the FIWO is located approximately midway between the two platforms.

The oil is produced and is subjected to initial water separation and de-gassing on each of the two platforms The resultant crude oil water emulsion IS pumped to the FPSO. The production module located on the vessel contains a second stage of separating, and a dual-stage dcsalting module. The resultant product crude 0il has a vapor pressure of less than 13 psia at 135, contains less than 0.5%BJS&W and less than 20 PTB (pounds per thousand barrels) of salt It is sent to storage tanks located with the vessel's hull off-loading occurs at intervals based on the production rate from the platforms

Each facility is designed to handle a peak production rate of 46 MBOPD through 16 producing well the producing wells each have an electric submersible pump (ESP) installed The maximum production rate for any one of the wells will be 10 MBPD total fluids. Along with the producing wells, there will be 5 or 6 water injection wells on each platform to provide a water flood mechanism to each reservoir. Water injection facilities will be designed at a future date.

The facilities on each platform provide for both the primary crude flashing and removal of free water. The crude and remaining emulsion is heated to 180° F and pumped to the FPSO each platform is connected to the FPSO by a sub-sea pipeline with pipeline end manifold (PI.IIM) and flexible riser.

The FPSO contain a dual-train process allowing stabilization, dehydration and desalting of the crude oil prior to storage and sale Disposal of the separated produced water overboard is in accordance with National Environmental Protection Agency (NFYA) water quality standards

The crude from these two fields contains a high concentration of wax has a relatively high pour point temperature. The crude composition and oil properties are listed in Tables 1 and 2 Special consideration was needed with respect to operating temperatures, start-up and shutdown procedures
Wide Tow Marine Seismic Surveys: Parallel or Opposite Sail Lines
Authors: Brink Mundy , Roberts Graham , Ronen Shuki
Published: October 2008

Wide tow seismic surveys include multiple streamers dragged behind the boat with streamers laterally offset by up to hundreds of meters from the sail line. Each sail line, or pass, thus provides a coverage of a few hundred meters wide. It allows an increase in the pass interval, a reduction in the number of passes and in the acquisition cost.

While wide tows are effective to reduce the acquisition cost, they provide data which may be problematic to image. If the acquisition and processing do not take into account the dip-dependent coverage, the output image may have severe amplitude and phase distortions.

The problem is that the sub surface coverage of a wide tow pass depends on the subsurface structure. On flat reflectors the reflection point is under the midpoint between shot andreceiver. This provides coverage which extends half way to the outer streamers on each side of the sail line. On dipping reflectors, however, the coverage is wider than half way to the outer streamer for down dip reflectors and narrower than half way for up dip reflectors. This creates problems for the imaging of up dip reflectors.

It is therefore recommended to alternate sailing direction between adjacent passes. Thus the narrowing of the coverage of one pass will be compensated by the widening coverage ofits neighbors. Because of variations in shooting directions we require an additional correction for receiver movement.

For old data collected before this phenomena had been noticed. or in cases where alternating sailing direction is notdone. advanced processing such as Inversion to Zero Offset (IZO) can produce acceptable results. However, the AVO gradient ay suffer from an acquisition footprint on dipping reflectors.

Introduction

Increased density of spatial sampling in a cost effective way was made possible for 3D marine seismic surveys by the deployment of multiple sources shooting into a distribution ofmultiple cables. A typical state of the art configuration consists of dual sources and a series of streamers covering a swath of several hundred meters with each boat traverse. In order to understand and quantify the impact of these marine acquisition geometries on final processed data quality, a study was initiatedby Saga Petroleum and Geco-Prakla. Brink and Larssen1 described results from the first phase of this study which focused on the impact of the acquisition geometry on the applicationof DMO techniques. This paper is a continuation of this work. It describes the impact of wide tow marine acquisition on DMO and suggests methods for improvement.

Wide towing becomes an issue since seismic data acquired from a single source shooting into a wide cable configuration requires careful handling with regard to the application of processing algorithms which assume 2D geometries and those which are dependent on regular dense spatial sampling. We know that poor spatial sampling adversely affects the performanceof wave equation based processes such as dip move out (DMO) and migration2.
Quantifying Seismic Amplitude Distortions Below Salt
Authors: Muerdter D.A. , Lindsay A.O. , Ratcliff D.W.
Published: October 2008

Interpretation, drilling, and discovery of subsalt reservoirs has been enabled by development of 3-D prestack depth migration of large marine 3-D seismic surveys. Although this technology has greatly improved imaging below salt, questions remain about amplitude variations in the data. This investigation uses raytrace modeling to study the aerial variations in the amplitudes of the subsalt reflections causedby complex salt structures and by large overlying velocity variations. The ultimate goal of this research is to understand the distortions and subtract them from the data, so that themore subtle variations in the seismic response caused by gas, oil. or brine in the reservoir rocks may be ascertained.

A 3-D computer model was built from the seismic and velocity volumes prodUced by 3-D prestack migration. Northsouth and east-west oriented 3-D seismic surveys were simulated in the model using Landmark's QUIKSHOTprogram. The raytracing results were sorted into reflection point gathers similar to the migration process used in 3-D prestack depth migration. Maps of the rays that hit a reflection-point bin and of the total and average amplitude per bin were prepared and analyzed. The following results were produced:Below the salt, hits per bin vary from 0 to 200 for data shot with geometric 30-fold coverage.The tota1 amplitude per bin varies by more than an order of magnitude.The edges of the salt bodies cause extensive distortion because of the salt's steep slopes and the bending of the rays that pass through the salt compared to those that do not.The salt shapes are so complex that generalizations are difficult and 3-D seismic modeling is needed to understand subsalt coverage.There are large differences in subsalt coverage between surveys shot in different directions. A multi-directional 3-D shoot would add significantly to the true reflection-point fold in most areas under sall

Introduction

As of December 1996, at least 7 subsalt discoveries have been reported in the Gulf of Mexico (Moore and Brooks, 1997) 1. A significant contribution to these successes was the availability of prestack depth migration (PDM) of 3-D seismicsurveys. In many areas the advent of 3-D PDM enabled imaging of the subsalt structures for the rust time (Ratcliff and Weber. 1997)2.

But areas still exist that are difficult to interprel Figure 1 shows a north-south line from the 3-D prestack depth migrated line over the Mahogany No. 1 discovery well. Near the well horizons are mappable. But to the north the subsalt data is difficult to interpret. Under the edges of the salt thedata become noisy and it is difficult to follow a reflector through this area. This study uses raytrace modeling to explain the seismic response observed below salt and to identify improvements in data acquisition. Another reason touse raytracing is that most 3-D prestack depth migrations currently use raytracing to move the energy recorded to its proper spatial position.
International Alliances: Closing the Cultural Gap
Authors: Farrell Susan , Watzke Jerry
Published: October 2008

As alliances become increasingly common around the world, differences in cultural expectations and the use of language have taken on a new and critical importance. This study examines the importance of cultural issues in the successful implementation of projects where participating companies are linked in a risk/reward agreement.

The review of alliances, including British, American, Canadian, Australian, Arab and Asian companies, revealed that strongly ingrained national cultural characteristics such as acceptance of authority and position in a hierarchy, style of communication, and perceptions of risk stongly influenced the ways in which a team functioned. In addition, however, there were very clear industry and company cultures which were overlaid on the national traits. The interplay of the three detennined the willingness or not of different members to adhere to such basic alliance principles as openness, egalitarianism and empowennent.

In no case did we find that the alliance members were given any cultural training nor were they particularly familiar with their partners' national, industry or company cultures. Often it was only after the project was underway, and the joint targets had already been set, that the members clearly understood thatdifferent interpretations existed of the so-called agreement.

Although the energy industry has long dealt with multiple nationalities, the introduction of alliance structures has greatly enhanced the need to understand and to incorporate differentcultures into the functioning of the team. Clear communication becomes a key element in the setting of alliance nonns and goals and the recognition that English will be interpreted in different ays is important in maximizing alliance results.

Introduction

Alliances are becoming increasingly commoll' in the international energy industry as operators search for ways in which to improvethe economics of projects. Even originally skeptical managers have come to believe that the dynamic created in an open environment, with different companies sharing ideas, creates more savings than would have occurred using traditional, segregated ways of working.

Alliances have now spread outside of the US and UK to embrace projects in the Middle East and Asia. As the use of this contracting structure grows, it will inevitably encounter successes and failures, attracting admirers and protagonists. But alliancing is here to stay. An understanding of the critical elements affecting the interactions among members will prove invaluable in constructing a set of partners with the greatest chance of success.

A previous study was conducted by the authors to identify key elements necessary for alliance success and published as OTC 8091, "Lessons Learned on International Partnering and Alliance Contracts"(l). Although not addressed in that paper, the research revealed the importance of cultural issues as an influence on alliance outcomes. The alliances surveyed here differ from those in OTC 8091 and were specifically chosen for their multi-national content.