bluuebunny/crossref_metadata_2025_split huggingface dataset:
Jackup Canti-Leg: An Extended Reach System
Authors: Childers M.A. , Song K.K. 
Published: October 2008

ABSTRACT
The requirement to drill, work over, recomplete, deepen, redrill or abandon wells on multi-well production platforms has increased and is increasing in the Gulf of Mexico. The conventional solution to do the latter has been to obtain a cantilever jackup, a jackup with a skid off capability, or a platform rig. Most multi-well platforms can accommodate one of the latter tools; however, there are a number of situations in which these approaches are either physically or economically unfeasible. Platform rigs require a lot of space, are heavy, require high mob and demob cost with long rig up (R/U) and rig down (R/D) times. Waiting on weather for loading is not uncommon. Platform production shut-in is required while R/U, R/D and maybe for the entire time if critical production equipment must be moved to make space for the rig. Jackup rigs spud canholes in the wrong place, pipeline(s), platforms with structural or equipment obstructions, well clusters that are out of reach of the cantilever extension, or the requirement to cantilever to the extreme with severely reduced set-back and hook loads may inhibit their effectiveness. Jackup skid-off rigs take platform space which mayor may not be available, requires long R/U and R/D times, and required production shut-in during R/U and R/D. The use of "macaroni" or platform self erecting rigs with small hook load capabilities (200,000-300,000 Ibs) have been tried many times with limited success when the latter options were unacceptable. In essence, reserves are being left in the ground due to a lack of equipment capability.
The "canti-leg" jackup, an abbreviated name for cantilever-leg, is a portable, self erecting, compact structural support system that can be used with most cantilevered jackups main cantilever beams. It converts the cantilever beams into simply supported beams, which result in full rated hook, set back, etc., loads at up to 70 foot and in some cases 90 foot extension. The relative motion between the production platform and jackup is absorbed via a bearing assembly that is mounted on the "A" frame support sitting on the platform. The canti-Ieg is an attractive and economic alternative to reach wells on multi-well platforms that were uneconomic and/or impractical with other methods.

NEED AND REQUIREMENT
When jackup drilling rig designs evolved during the 1950's and 60's, a slot was placed at the aft end of the rig in which the well being drilled would fit. The first rigs had a rather small slot in which one, two or possibly three wells could be drilled on close spacing. This was accomplished by the rig being stationary and the crown block or the substructure being skidded port or starboard as well as forward or aft. As time evolved, the slots became bigger of which the standard is now approximately 50' × 50'.
Subsea Flexible Pipeline Burial Using A Lightweight Pipeline Trencher
Authors: Dansette Nicholas , Robertson N.C. 
Published: October 2008

ABSTRACT
During 1993 a flexible, lightweight flexible pipeline trencher successfully trencher over 140 km of pipeline to 1.5 meter burial depth. This paper provides an overview of the system with emphasis on specific operational results with specific contracts. Results covered will be amount and depth buried, soil bottom changes, burial speed, remedial work, backfilling, and operational factors/limitations encountered.

INTRODUCTION
Flexjet I was designed and fabricated in the first six months of 1992 with the goal of providing operational results at the end of 1992 to allow preparation for the 1993 operational season. The trenching system and overall concept design was a cooperative effort between Coflexip and Perry Tritech Inc. The concept goal, and final result, was to provide a lightweight pipeline trenching system based around proven Perry Tritech ROV products and systems incorporating Coflexip experience in pipeline burial.

FLEXJET GENERAL OVERVIEW
The Flexjet is a free flying, lightweight (12 tonne) pipeline burial vehicle that incorporates standard TRITON? systems technology. The 400 HP water jetting system is electrically and hydraulically controlled by a 100 HP TRITON? ROV which is located in the center of the Flexjet vehicle. The Flexjet has a set of tracks that are used during burial operations and general bottom crawling. When transiting to the operational area on the seabottom the Flexjet is neutrally buoyant and "flies" as a standard ROV. Once on the seabottom the vehicle can be ballasted down by bringing onboard 1.5 tonnes of water with the Variable Ballast System (VBS). At any time the vehicle may be deballasted and flown again as a standard ROV. Transition from neutral buoyancy to full ballast (or deballast) is about 20 minutes. The 1.5 tonne ballast load during crawling allows a 1.0 tonne draw bar pull of the Flexjet.
Trenching results are obtained with 400 total horse power of jetting power split between high pressure and low pressure jetting systems.
The high pressure jetting system consists of 2 X 125 HP pump/motor sets. The high pressure jet on the trenching arms face forward into the direction of Flexjet travel and are used to cut or fluidise the soil. Each 125 HP assembly produces 6,623 LPM at 8.5 bar.
The low pressure clearing jet systems consists of 2 X 75 HP motor/pump assemblies. The low pressure jets on the trenching arms face aft and are used to clear the fluidised soil from the trench as it is fluidised by the high pressure jets. Each 75 HP assembly produces 13,247 LPM at 1.7 bar.
Several sets are trenching and backfilling arms are available with the Flexjet system. This array of rapid change arms are:0.5 meter burial arm set1.0 meter burial arm set1.5 meter burial arm set2.0 meter burial arm setTwo types of backfilling arms
All arms are flange mounted and can be changed on deck in 30-40 minutes.
Design And Installation Of Auger Steel Catenary Risers
Authors: Phifer E.H. , Kopp Frans , Swanson R.C. , Allen D.W. , Langner C.G. 
Published: October 2008

ABSTRACT
The Auger export pipelines are connected to the TLP by steel catenary risers (SCRs). This is believed to be theftrst time steel pipe has been used for catenary risers. SCRs offer advantages over tensioned risers, since SCRs need no heave compensation and no subsea connections, and over risers made of "flexible pipe", since SCRs are much less expensive. However, significant design effort was required to prove that the SCRs could safely withstand environmental loads and the effects of TLP motions. The design effort consisted of extensive dynamic analyses as well as full scale fatigue testing of both the riser joint welds and the flexible joint that connects the riser to the TLP pontoon. Devices which suppress vortex induced vibrations were also tested. SCR installation is accomplished by lowering the riser on the abandonment and recovery cable from the J-Lay installation vessel and transferring the riser on a chain that is run through a chain jack hung from the TLP upper deck structure. A special Installation and Maintenance System was built for this purpose.

INTRODUCTION
Oil and gas export pipelines are connected to Shell's Auger Tension Leg Platform (TLP) by steel catenary risers (SCRs). Each SCR is essentially an extension of the pipeline [1], suspended in a near-catenary shape from a TLP pontoon to the seafloor. See Figure 1. The SCRs are composed of steel pipe sections welded end-to-end, terminating at a flexible joint which is supported by a receptacle mounted on the pontoon. Piping is routed from the deck down a TLP column and along the pontoon, where there is a flange connection to the top of thei1exible joint. This is believed to be the first application of steel pipe for catenary risers.
SCRs offer advantages over risers made of "flexible pipe" since SCRs are much less expensive. SCRs also offer advantages over top tensioned risers since SCRs need no heave compensation, no subsea connections, and no flexible jumpers to transition to fixed piping at the production deck. For some applications a disadvantage of catenary risers compared to top tensioned risers is the length of active footprint on the seafloor, but this is not the case for Auger.
Each SCR has an outside diameter of 12.75 inches and a wall thickness of 0.688 inch. The pipe material is API 5LX-52. The entire riser has a triple coat epoxy/polyethylene coating for corrosion protection and high abrasion resistance in the touchdown area. The upper 500 feet has a 0.5-inch thick neoprene coating for additional protection and marine growth prevention, plus triple-start helical strakes for suppression of vortex induced ibration (VIV). The flexible joint provides a rotation capacity for the upper end of the riser of ±14 degrees from the installed orientation of the riser, which is 11 degrees from vertical. See Figure 2. The maximum operating pressure is 2160 psi and the maximum operating temperature is 100 degrees F.
Design, Fabrication, And Loadout Of Auger Hull
Authors: Luyties W.H. , Balint S.W. , Smith P.L. , Pellegrini Umberto , Chianis J.W. 
Published: October 2008

Abstract
The Auger Tension Leg Platform (W) hull is a 73,000 st displacement structure weighing 21,500 st. It consists of four stiffened cylindrical columns connected by four stiffened rectangular pontoons and operates at a mean draft of 94 ft. The structure was designed for in-place conditions using both time domain analyses to capture non-linear wave load effects and linearized frequency domain analyses. Extensive use was made of finite element analyses (FEA) to design structural components. The hull was fabricated by Belleli S.p.A. in Italy on Iandskidways, Ioaded onto two submersible barges, and floated off in preparation for a wet transport across the Atlantic Ocean. Throughout the fabrication, Shell and Belleli engineers and site construction personnel worked closely together to insure that the final product was a cost effective and fit-for-purpose structure. As a result of the work performed on the Auger hull a number of important lessons were learned that will be applicable to the next TLP hull and should result in an even more cost effective structure.

Design

Configuration
The Auger TLP hull is a 73,000 st displacement structure supporting an operating payload of 17,800 st, including deck steel, topsides facilities, and riser tension, and tendon pretension of 12,000 st. It consists of four cylindrical columns connected by four rectangular pontoons and is held on location by 12 tendons and 8 mooring lines. The columns are 74 ft in diameter, stiffened longitudinally and circumferentially, with a 34 ft diameter inner shell, stiffened circumferentially. The pontoons are 28 ft tall by 35 ft wide boxes, made up of orthogonally stiffened flat plates. In the short direction the column centerlines are spaced at 214 ft, while in the long direction the spacing is 264 ft. The hull will operate at a nominal draft of 94 ft although an additional 5 ft of draft can be accommodated for possible subsidence due o reservoir compaction. Figure 1 summarizes the principle hull dimensions. The total weight of the hull is approximately 21,500 St.
The hull is subdivided into compartments by horizontal flats in the columns and vertical bulkheads in the columns and pontoons. Pontoon compartments are permanent ballast tanks, as are the perimeter column compartments at pontoon level, All other compartments are void tanks, Compartment size is selected to prevent tendons going slack under the reduced extreme environmental condition (1 year return period hurricane or 10 year winter storm) with compartment damage and compensating ballast to even out the tendon loads, Damage is defined as two compartments flooded at the waterline or one compartment flooded elsewhere, The keel inside the inner shell is protected by a double bottom; consequently, the inner shell compartment is not considered susceptible to damage.
A pumproom is located at the keel inside the inner shell at each column, with a 7 ft diameter access tunnel connecting each pair of pumprooms through the short pontoons.
Response Based Design Conditions in the North Sea: Application of a New Method
Authors: Romans Peter S. , Vandersohuren Luc 
Published: October 2008

SUMMARY
The estimation of rare, extreme environments from a relatively short oceanographic database is crucial to the calculation of loads and responses of offshore structures. A novel and consistent approach has been developed that makes use of a number of asymptotic properties of extremes. A storm can be adequately characterized by its most probable extreme wave or the resultant structural response. This allows us to treat storms, rather than sea states, as the essential random, independent events; to account correctly for uncertainty in the largest wave and structural response within a storm; and to deal with the uncertainty in the seventy of randomly arriving storms, including the rare storms that are more severe than those in the database. The method provides the long term load statistics essential to reliability analysis and to the calibration of environmental load factors in design codes.
We demonstrate the application of the method to the prediction of extreme waves, loads and "response based" environmental design conditions for a drag dominated structure in the North Sea.

INTRODUCTION

The estimation of extreme waves.
The loads induced by extreme storms are critical in the design of offshore structures for location in severe seas, The load arises References and figures at end of paper from a combination of waves, currents and wind, though waves are generally the dominant factor. The problem of specifying meteorological and oceanographic (met-ocean) design conditions is one of estimating these environmental variables corresponding to some return period, typically 100 years, on the basis of measured or hind cast time series extending over a relatively short period, 5 to 25 years. For the North Sea and some other areas, a widely used approach to obtaining design wave heights has involved fitting cumulative distributions to the significant wave heights of successive three hour sea states[1,2]. U is common to neglect both the correlation between successive sea states and uncertainty in the extreme wave of a sea state. In spite of this, the distributions are used to estimate a 100 year return value. Similar processes are used separately foreach met-ocean variable. The consequent 100 year wind, 100 year wave and 100 year current are conservatively assumed to occur simultaneously and act in the same direction. For a typical jacket structure, this will lead to a "design load" that is much more severe than the "true" 100 year load.
Submarine Gas Hydrate Estimation: Theoretical and Empirical Approaches
Authors: Ginsburg G.D. , Soloviev V.A. 
Published: October 2008

ABSTRACT
The published submarine gas hydrate resource estimates are based on the concepts of their continuous extent over large areas and depth intervals and/or the regionally high hydrate concentrations in sediments. The observational data are in conflict with these concepts. Atpresent such estimates cannot be made to an accuracy etter than an order of magnitude. The amount of methane in shallow subbottom (seepage associated) gas-hydrate accumulations is estimated at 1014m3 STP, and in deep-seated hydrates at 1015 m2, according to observational data. From the genetic standpoint forthe time being gas hydrate potential could be only assessed as far less than 1017m3 because rates of related hydrogeological and geochemical processes have not been adequately studied.

INTRODUCTION
Natural hydrates frequently occur in outer continental margins and deep-water inland seas and lakes covering bout 10% of the total water area. However the estimates of their abundance that have been made are speculative. The published estimates derive from the concepts of their continuous extent over largeareas and depth intervals and/or of the regionally high hydrate concentrations in sediments. Meanwhile, the analysis of the world wide data suggests that submarine hydrates locally occur, largely in accumulations. The aims of this paper are to substantiate the local nature of the submarine gas hydrate distribution and to try to estimate their abundance from the observational data and the geological notions of their formation.

2.REVIEW OF PREVIOUS ESTIMATES
Two recent papers3,4 have presented the overviews of submarine gas hydrate methane content. For brevity we shall consider only the published estimates which are based on the adequately justified underlying data. These estimates4,6 ranging within the limits (1.8-13.91) × 1016 m3 STP have resulted from themultiplication Q = S × h × K × Z × E and relies on three different concepts. One such concept4,6 assumes gas hydrates to occur within the HZ through the sediments relatively enriched with organic, matter (in the papers5,6, Corg &gt; 1%). The range of the obtained values (2.0-13.9) × 10"6 m3 depends mainly on the adopted values of S (1 × 107 to 3.17 × 107km2v) and Z (5 to 10%). Another concept5 deals with seismic records. It was inferred from seismics that in the Beaufort Sea gas hydrates occupy about 75% of the band-like area of 7 × 105 km2 extending along the continental slope at water depths from 400 to 2800 m. They were supposed to completely fill pores of the lowermost 40 m of the HZ where porosity was 30%. As the length of the studied area is 20 times less than the total length of continental margins, Qg was calculated as 20-fold Qr and constituted 1.8 × 1016 m3 The third concept" starts from the fluid migration odel" in which hydrates are precipitated from fluids ascending from under the HZ. According to this model, S (2.3 × 107 km2) includes the area of accretionary prisms and regions of high Cenozoic sedimentation rate, and Z is assumed to be equal 50%.
Hydrostatic Collapse Research In Support Of The Oman India Gas Pipeline
Authors: Stark Peter R. , McKeehan David S. 
Published: October 2008

ABSTRACT
This paper provides a summary of the collapse test program conducted as part of the technical development for the Ultra Deep Oman to India Pipeline.
The paper describes the motivation for conducting the collapse test program, outlines the test objectives and procedures, presents the results obtained, and draws conclusions on the factors affecting collapse resistance.

INTRODUCTION
Oman Oil Company (OOC) is implementing the 1139 km Oman to India Gas Pipeline Project (OIP). The pipeline will cross the Arabian Sea, initiating at Ra's al Jifan in Oman with landfall at Rapar Gadhwali in India, and will encounter a maximum water depth in the Dalrymple Trough of 3525 m, This is over three times deeper than any pipeline yet laid, Fig, 1 shows the principle features of the route.
Likely methods of installation include J-lay and reeling, both of which result in bending strain in the sagbend near the seabed whilst reeling also applies a bend and straightening technique which results in residual ovality after straightening. Tension and bending are known to reduce the collapse resistance of pipe and, during installation, these factors, in combination with a maximum bottom pressure of 35.4 MPa (5135 psi), make the possibility of pipe collapse due to external hydrostatic pressure a major factor in the pipeline design.
Gas throughput requirements necessitate a minimum internal pipeline diameter of 24 inches and, based on existing collapse design theory, preliminary engineering selected a 24-inch ID × 1.625-inch WT (max) grade X-70 material for the pipeline.
To achieve a realistic production rate, the use of UOE pipe is required, however, little or no data is available on the collapse performance nor on the combined effect ofpressure and bending for UOE pipe of this diameter and D/t ratio (17.2).
In order to address these and other issues, and as part of he overall pipeline design verification process, OOC instigated a comprehensive collapse testing program which began in March 1994.

MOTIVATION FOR TESTING
Although a good body of literature exists on the general theory of pipe collapse, specific tests this project for the following reasons:Existing collapse pressure data on large diameter, low D/t UOE pipe is very limited.Data on collapse under combined bending and pressure does not exist for such pipes.The collapse pressure of pipe manufactured by the UOE process has consistently been found to be lower than that of pipe of the same grade produced by different manufacturing processes.There is little data available regarding buckle arrestor performance for this diameter and D/t pipe and it is therefore necessary to validate any buckle arrestor design experimentally.

SCOPE OF TESTING
The test program comprised four parts.
Part 1 involved the straight collapse testing of 20-inch OD × 1.1 25-inch WT, X65 pipe specimens each approximately 4,5m (15ft) in length. Part 2, 3 and 4 tests used 26-inch OD × 1.625-inch WT, X60 pipe specimens approximately 8.8m (29 ft) in length.
DEEPSTAR 902 Cloud Point Round Robin
Authors: Williams T.M. , Santamaria M.M. 
Published: October 2008

ABSTRACT
Wax deposition is a problem in many oil fields and wells. Since wax precipitates and may cause deposition problems when the oil is cooled below its cloud point, an accurate method to determine an oil's cloud point is needed.
Samples of oil from three wells were collected and distributed to ten laboratories. The results indicate that cloud point temperature measurement is not as well defined as expected. The results of this study are discussed in this paper.

INTRODUCTION
The objectives of this project were to:compare methods of measuring cloud point temperatures,explain why methods yield differing results,illustrate data deviation, andrecommend suitable techniques.
At the request of. the Deepstar 900 Study Group, samples of oil from three wells in the Gulf of Mexico were collected and distributed to ten laboratories forcloud point measurements.
Most methods used were able to determine a cloud point within 10°F of the average cloud point determined by all methods. A discussion of the results and the analysismethods used follows.

DISCUSSION
Sample Collection and Dktribution Methods Samples from three wells were collected in new, five gallon cans. Sampling instructions and well conditioning suggestions were shipped to the field with the empty cans.
After the three samples were received by the authors, each sample was immersed in a hot water bath at 150° F. While the samples were being heated, theywere mixed with a 3 blade paddle stirrer connected to a variable speed electric motor. After each sample washeated and mixed, it was pumped from the sample container into 10 different containers for distribution.

Experimental Equipment and Procedure
The three samples were sent to 10 different laboratories for cloud point measurement. Some laboratories used multiple methods to measure the cloud points; therefore, 12 techniques were studied. Three laboratories used DSC techniques and three used viscosity techniques. Though similar techniques were followed, procedures varied and so did results. Short descriptions of the measurement techniques are given below.

Lab 1-Cross Polar Microscopy
A cross-polar microscope was ficatiom A video was used at used at × 125 magnithe temperature stage. The sample was heated to 176 °F and cooled to 140 °F at 1.8 °F/min. It was then cooled from 140 °F to 32°F at 0.18°F/min. Onset of crystallization was recorded asthe cloud point.

Lab 2-Viscometer, Brookfield
The sample was heated to 150°F. The viscosity was measured using a special low viscosity spindle. Cloud point was detected as a change in the slope of the Iog(viscosit y) versus temperature curve.

Lab 3-Cross Polar Microscorpy
A sample was heated in hot water near 130°F in the original container and shaken to ensure no wax was left on the walls of the container. The entire sample was then poured into a 1 liter pressure vessel and heated(under pressure) to 180 °F for one hour to ensure that all of the paraffin was redissolved. After one hour, the temperature was dropped to about 150 °F.