bluuebunny/crossref_metadata_2025 huggingface dataset:
A New Approach to Quasi-Newton Methods With Application to Compositional Modeling
Authors: Nghiem L. X.
Published: December 2007

A new approach to quasi-Newton methods for nonlinear equations called quasi-Newton successive substitution (QNSS) is proposed. The use of QNSS does not require the computation nor the inversion of the Jacobian matrix at every iteration. Hence for large sparse systems which arise from the discretization of the reservoir flow equations, substantial savings can be achieved.

The new method is applied to the solution of the pressure equation associated with a compositional model. An example shows the drastic improvement in convergence which can be achieved with QNSS compared to a previously published technique. The handling of gas solubility in the water phase using three-phase oil-gas-water flash calculations is also described.

The QNSS method is very general and can be applied to any existing simulators.
A Comparison of Three Equation-of-State Compositional Simulators
Authors: Thele K. J. , Lake L. W. , Sepehrnoori Kamy
Published: December 2007

The compositional equation of state formulations by Coats (C), Nghiem, Fong, and Aziz (NFA), and Young and Stephenson (YS) are compared for both immiscible (IM) and multiple contact miscible (MCM) problems. Coats' formulation has the largest computer memory requirements and computation times. Nghiem, Fong, and Aziz's formulation requires the least memory, and Young and Stephenson's formulation is generally the fastest.
Finite Difference Solutions to Grid Orientation Problems Using IMPES
Authors: Bertiger W. I. , Padmanabhan L.
Published: December 2007

It is well known that numerical solutions by the standard five-point differencing schemes for two-phase flow equations exhibit grid orientation effects in two and more dimensions. To minimize such effects nine-point differencing of the differential operator is often proposed, such as the recent formulation by Yanosik and McCracken (1). However, it has been observed that this approach does not give satisfactory results in the case of non-uniform grids. An alternate nine point formula is proposed based on a more accurate integration of fluid fluxes across cell faces. Numerical results are presented which demonstrate that this formula greatly reduces the sensitivity to grid orientation in both uniform and nonuniform grids.
Enhancements to the Strongly Coupled, Fully Implicit Well Model: Wellbore Crossflow Modeling and Collective Well Control
Authors: Holmes J. A.
Published: December 2007

A strongly coupled well model is described for use in a fully implicit 3-phase reservoir simulator. The model uses three variables for each well, instead of the usual single variable representing the well's bottom hole pressure. The two extra variables describe the contents of the wellbore, and provide a means of modeling crossflow of fluid between reservoir layers through the wellbore.

For each of the standard modes of well control, it is possible to express the well flow rates in terms of the three well variables alone. This provides a convenient means of handling fully implicitly the collective interactions between wells that occur with group and field production rate control and re-injection or voidage replacement operations. An example simulation is presented, to illustrate the capabilities of the fully implicit collective well control algorithm.
The Use of Adaptive Grids in Numerical Simulations
Authors: Goslinga Jentje
Published: December 2007

A new method for generating adaptive grids is presented. The transformation of a general nonlinear heat equation to arbitrary moving coordinates is derived. Typical aspects of solving equations in moving grids are discussed, in particular the conservation of mass as well as volume. A new method for constructing discretizations to conservation equations is presented, and applied to the nonlinear heat equation.
Analysis of Growth and Interaction of Multiple Hydraulic Fractures
Authors: Narendran V. M. , Cleary M. P.
Published: December 2007

A general-purpose numerical formulation is presented for the incremental quasistatic stable lateral growth and interaction of fluid driven fractures in reservoir structures. Multiple fractures emanating from multiple wellbores are allowed to evolve on arbitrarily curved trajectories, dictated by non-uniform stress fields arising from interaction of fractures with one another and with material/stress variations. The model simulates fracture growth by simultaneously solving for stresses, displacements and pressure distributions associated with the fracturing configuration at each timestep. The elastostatic computation employs a surface integral method, while the coupled fluid flow and crack opening modelling involves a weak starting assumption of (instantaneous) self-similarity in the opening displacement profile. A search scheme is used to determine the directions and amounts of growth at the end of each timestep. Several sample fracture growth patterns are presented to illustrate the generality and applicability of the simulator, which is verified by comparison with many of our laboratory experiments. The overall scheme provides an efficient, direct and convenient tool for design of multiple fracturing treatments, whenever these begin to be used for creation of suitable underground fracture networks (e.g., for enhanced petroleum recovery or solution mining).
A Method of Data Management in a Simulator Used for Large Reservoir Models
Authors: Eccles T. K.
Published: December 2007

A software package has been developed to manage the transfer of data arrays back and forth between central memory and temporary disk storage. It was designed for and installed in a reservoir simulation program to provide the capability of simulating models containing in excess of 30,000 gridblocks. The simulator runs on both IBM and CRAY systems.

Simulator routines with array arguments are called via the disking package, which first ensures that needed arrays are in memory. If all arguments do not fit in memory, the package calls the routine repeatedly, each time with a different range of array elements until the full array range has been covered.

Often, arrays to be brought into memory do not fit into the randomly distributed existing empty memory spaces, even though the total empty space is sufficient. An efficient algorithm has been developed to handle this problem with a minimum amount of shuffling of existing memory contents.
Development of Fracture-Enhanced Reservoirs in Upper Devonian Sands and Shales
Authors: Tillman J. E.
Published: December 2007

Fracture-enhanced reservoirs are widespread in the middle and upper Devonian sands and shales of the Appalachian Basin. These zones of fracture enhanced permeability and productivity can be delineated with surface and downhole geochemical techniques. Careful use of surface geochemical surveys can greatly improve our ability to target and develop these resources.
A Field Test of the Strain Recovery Method of Stress Determination in Devonian Shale
Authors: Blanton T. L. , Teufel L. W.
Published: December 2007

The strain recovery approach to in situ stress determination was applied to transversely isotropic Devonian shale core obtained from Meigs County, Ohio. The temperature-corrected recovery strains showed expansion in all directions for a period of about 30 hours. During this time, the average azimuth of the maximum recovery strain was N70E ± 2°. The calculcated magnitudes of the maximum and minimum horizontal compressive stresses were about 1.5 times and .8 times the overburden, respectively. Attempts to measure the stresses by hydraulic fracturing at the same site produced inconclusive results. However, the results of the strain recovery approach at Meigs County appear to be consistent with published results from hydraulic fracturing measurements made in other parts of the Appalachian Basin.
Pressure Transient Behavior of Dilatant Non-Newtonian/ Newtonian Fluid Composite Reservoirs
Authors: Okpobiri G. A. , Ikoku C. U.
Published: December 2007

This study investigates pressure falloff testing in non-Newtonian/Newtonian fluid composite reservoirs. The non-Newtonian fluids of interest exhibit dilatant behavior. Initial water saturation is accounted for. Application of non-Newtonian well test analysis techniques and conventional Horner (Newtonian) techniques is investigated. The effects of different injection times before shut-in, external radii, flow behavior indexes and non-Newtonian fluid consistencies on the pressure transient behavior constitute the salient features of this work.

It is shown that early time falloff pressure data can be analyzed by non-Newtonian techniques while the late shut-in data, under certain conditions, can be analyzed by the conventional Horner method. The time when the Newtonian fluid starts influencing the non-Newtonian falloff curves and the location of the non-Newtonian fluid front can be estimated by using the radius of investigation equation for power-law fluids and volumetric balance equation respectively. Rheo-logical consideration is made to illustrate the pressure transient behavior.
Oil Recovery With MERCO Fluids
Authors: Klins M. A. , Ireland M. M.
Published: December 2007

The major objective of this study was to evaluate a new fluid injection scheme for recovering tertiary oil. These fluids, developed by the Molecular Energy Research Company (MERCO), appear to be composed primarily of sodium silicate and ammonia as well as other undisclosed, unidentified additives.

In particular, a series of core flood experiments were conducted along with various fluid property measurements. Two of the MERCO fluids were tested with Delaware–Childers crude oil (35°API), two others with Bakersfield crude oil (15°API). Prior to tertiary flooding the cores were water-flooded with sodium chloride brine.

Recoveries for the Delaware–Childers floods using a continuous injection of Merco of Si-Na (NH2CONH2) fluids recovered from 3.9 to 35.4% of the tertiary oil. Oil response increased as the flooding rate increased from 1 to 5 ft/d. Much of this recovery could be credited to the gas drive created when the hydrogen peroxide used in the tertiary fluid decomposed in the core. Floods utilizing hydrogen peroxide alone recovered 6.4 to 20.5% of the tertiary oil and showed the same rate dependence .

The core floods conducted with Bakersfield crude oil and slugs of C–4–L and C–8–5 test fluids chased by polymer had recoveries ranging from 14.3 to 18.8% of the tertiary oil in place. Recoveries with C–4–L increased as slug size was increased from 1.6 to 10.0% of the pore volume, while C–8–5 flooded cores showed no change in recovery. Most of this recovery was attributable to the polymer buffer used for mobility control. Polymer injection alone recovered 14.1% of the tertiary oil.

Crude oil – aqueous phase interfacial tensions were reduced 58 to 92 percent with the MERCO fluids. This is not enough to significantly alter recovery. The MERCO type fluids were also able to break water–oil emulsions more quickly than gravity alone. However, a commercial demulsifier was much more efficient than any of the MERCO fluids tested for this oil–water system.
Foamed Anhydrous Methanol Stimulation
Authors: Craighead M. S. , Hossaini Mohammad , Watson R. W.
Published: December 2007

Laboratory studies have indicated that foamed anhydrous methanol may be an effective stimulation technique for the sands and shales of the Appalachian Basin and the Eastern Overthrust Belt. These formations are characterized by low pressures, low permeabilities, and sensitivity to injected water. Conventional aqueous fracturing foams pumped into these formations result in fluid retention, clay swelling, and migration, along with capillary pore blockage. To forego such problems, some operators instead pump strictly nitrogen (N2) gas or liquid carbon dioxide (CO2) as the stimulation fluid. Such treatments minimize formation damage but are incapable of transporting appreciable quantities of proppant for the created fractures. Laboratory studies were conducted to determine a more effective stimulation fluid. Results indicate that foamed anhydrous methanol may be such a fluid because it is nonaqueous and capable of transporting proppant.
The Application of Manufactured Proppants in Moderately Permeable Oil Reservoirs
Authors: Norman M. E. , Cipolla C. L. , Webb M. L.
Published: December 2007

An analysis is made to determine the effectiveness of new manufactured proppants as compared to sand in a variety of moderately permeable oil reservoirs. Results of laboratory tests on permeability, conductivity, crush resistance and physical properties of sand and manufactured proppants are presented. The technical and economic aspects concerning the application of these proppants in oil well fracturing is explored. This is accomplished through the use of a reservoir simulator and a fracture design program. Oil producing formations between 4,000 feet and 10,000 feet having effective permeabilities between 0.10 md and 10 md are simulated. The simulations indicate that production and optimal hydraulic fracture design can be substantially improved in the higher permeability cases by using high performance manufactured proppants. Economic analysis indicates that the incremental present value obtained by fracturing can be increased by using a high performance proppant, even though proppant costs are increased.

The impact of conductivity damage and embedment are also studied with the simulator. It is shown that the affect of these factors on fractured well performance is reduced through the use of high performance manufactured proppants.

The combined results of the simulations indicate that some of the new proppants can be technically and economically effective in improving well productivity in a variety of oil well applications.
South East Asia in a Changing Oil World
Authors: Meloe Tor
Published: December 2007

Economic growth in South East Asia accelerated in the past ten years. But a period of adjustment lies ahead, as it does for most of the Third World countries. Escalation of oil prices has slowed expansion of world oil demand and encouraged major consuming countries to switch to alternate fuels and to seek diversification of supplies in the interest of energy independence. Petroleum sales in Japan, the major outlet for oil exports from South East Asia, have stagnated, but exports to the United States offer a substantial alternate market as future domestic supply in that country falls off. By the year 2000, petroleum imports into the United States may total over 10 million barrels daily, double the level of 1982, if U.S. oil production declines as forecast. Greater penetration of this market by South East Asian producers may require a re-orientation of marketing strategies.
South East Asia: has an Activity Plateau Been Reached?
Authors: Keplinger H. F.
Published: December 2007

South East Asia is now preparing for one of the greatest periods of exploration activity in its history. Next to the United States, it will be the second largest area for new well activity in the world. Many are excited about the prospects because of some recent successes and because so little seismic activity has been done throughout the area.

If there is any plateau, it should only be considered as occurring for a brief period and due primarily to the worldwide recession and the lack of capital for investment. This problem has been shared by many other developing countries all over the world. As a result, many energy development plans have not undertaken as planned in South East Asia. However, overall exploration and rig activity has been stable during the last year. The results have been encouraging with finds in the South China Sea and the North West Shelf of Australia.

As a result of the push to develop their own energy sources, these countries will become prime areas for new investment. The energy investment needs will be substantial. Petroleum exploration and development may require as much as $28.2 billion in annual expenditures by 1990. (Ref 1)
Automated Production Control in Arun Gas Field
Authors: Scholz Warren E. , Aspoor Safri P.
Published: December 2007

This paper describes the objectives, equipment and functions of the Supervisory Control and Data Acquisition (SCADA) system installed by Mobil Oil Indonesia (MOI) during the first half of 1983.

The SCADA system provides operations, management, and engineering personnel with various applications of automatic production control such as production reports, field and cluster status, and flow calculations.

This paper concludes with a discussion of the particular benefits gained by MOI in the Arun Field as well as the features of the SCADA system which make it a potential model for similar systems throughout the petroleum industry.
The Development of a Highly-Integrated Offshore Oil and Gas Production System in the North Sea
Authors: Holding John
Published: December 2007

This paper covers a description of the evolvement and of the technical details of a highly-integrated offshore oil and gas oroduction system. The technical aspects of the specific oil and gas processing systems, which are located in the Danish sector of the North Sea, are the main areas covered by this paper. The intent of the original oil field establishment which is now some 11 years old, recent developments of other oil and gas fields, and a description of the offshore production capabilities for handling future fields, are presented herein. The aim is to show how significant offshore process integration of independent oil and gas fields has been achieved.
Malaysian Custody Transfer Metering Philosophy
Authors: Danir Nusral Bin
Published: December 2007

Custody transfer metering is part and parcel of the petroleum production operations. Every cubic metre of hydrocarbon produced has to be accurately measured. Measurement systems in the oil and gas industry have developed rapidly in terms of sophistication and usage of modern technology and Malaysia has to keep abreast of this development to ensure not only the accuracy of measurement, but also the reliability and accountability of the measurement systems.
A Review of Well Log Interpretation Techniques for Carbonate Reservoirs of South-East Asia
Authors: Cooke-Yarborough P.
Published: December 2007

Carbonate reservoirs, particularly those of Tertiary age, contribute significantly to South-East Asia's oil and gas production. There is considerable potential for more carbonate fields to be discovered in the future, because much of the region is still under-explored. Well logs recorded in these formations con, in many cases, be very difficult to interpret. Limestones and dolomites are hydrocarbon-bearing in Indonesia and the Philippines, as well as having good potential for hydrocarbon reservoirs around the fringes of the Indian and Australian land masses. Specific examples of recent well logging problems and their passible solutions ere drawn from these areas.

The choice of optimum well logging suites, to maximise the amount of petrophysicol information obtained from the carbonates, is discussed with some of the new, as well as the traditional, interpretation techniques, used in many other areas of the world. Some recent advances in logging tool technology are featured, and a variety of interpretation techniques are shown to have good applications, particularly natural gamma ray spectroscopy and formation testing by wireline methods. Much of this advance has been in the last five years, in large part due to the advent of digital computer wellsite recording. Methods to identify fractures and permeability indication techniques are reviewed, as well as potential uses of dip tools.
Structural Development and Hydrocarbon Entrapment in the Surma Basin/Bangladesh (Northwest Indo Burman Fold Belt)
Authors: Hiller K , Elahi M
Published: December 2007

The Surma Basin in the Northeast of Bangladesh is a proven Miocene Gasprovince and was structurally stamped by the contemporaneous interference of two major tectonic movements, ie. the emerging Shillong Massif in the North and the West-progroding mobile Indo-Burman Fold Belt. Basin relief, structural elements, growth and style as well as geochemical data with respect to hydrocarbons, source rocks and maturity are discussed. Related to the clear cut pre- and post-early Pliocene situation, change of migration pattern and coincidence between hydrocarbon generation, migration, accumulation and trap growth are analysed. Finally, the further prospectivity of the Surma Basin is commented upon.
Reservoir Compaction and Surface Subsidence in the Central Luconia Gas Bearing Carbonates, Offshore Sarawak, East Malaysia
Authors: van Ditzhuijzen P. J. D. , de waal J. A.
Published: December 2007

In the Central Luconia area, offshore Sarawak, substantial gas reserves are present in Miocene carbonate buildups. The carbonates consist of limestones and dolomites with porosities ranging from 0 to 40 percent. From core analysis it became evident that there exists a potential problem with regard to the compaction of the carbonate reservoir matrix as a result of effective stress increase as the reservoirs are depleted. Triaxial compaction tests were carried out on core samples from several carbonate reservoirs. It was found that highly porous mouldic limestones show pore collapse at relatively low effective stresses. After pore collapse the uniaxial compressibility coefficient increases significantly.

Reservoir compressibility parameters can be derived from core data, for collapsing as well as non-collapsing rocks. These can be used to calculate reservoir compaction from well logs for o particular pressure decline. An estimate of the expected surface subsidence can be made based on the theory of poro-elasticity and the nucleus of strain concept as described by Geertsma. Predicted subsidence figures have been taken into account in platform design.

The gas reservoirs have large aquifers within the carbonate buildups. As these aquifers have not all been fully appraised, there exists some uncertainty concerning their actual compaction behaviour.
Application of Jack-Up Rigs to Offshore Porduction
Authors: Harrail J. W. , Boon B. , Worley M. S.
Published: December 2007

The paper discusses the application of self-elevating platforms (jack-up rigs) to offshore production.

Particular emphasis is placed on South East Asia, where marginal field development of short life fields in relatively shallow water depth is a prime consideration.

Cost comparison between a jack-up rig and a fixed platform are discussed using an actual estimate of installed costs for σ specific field development. The technical features and limitations of the jack-up rig are also dealt with.
The Experimental Study on the Seakeeping and Capsizing of Self-Elevating Drilling Platforms
Authors: Tiecheng Feng , Shangsan Yu , Limin Dai
Published: December 2007

Self-elevating drilling platform is one of the types of offshore drilling units. In this paper, we describe briefly the problems regarding motion and shipping water on deck of platforms in waves. The causes of capsizing of a damaged platform are investigated by experiment, in which the ocean environments are simulated in the towing tank, and various influences of wave height, motions of the platform, damaged tank and shipping water on capsizing have been analysed.

The suggestion and conclusions on the seakeeping and the capsizing of platforms presented in the paper can be used in the design of platforms and operations under tow.
Feasibility Study: Pressure Maintenance of E-22 Reservoir, Ardjuna Field – Offshore Northwest Java
Authors: Harjadiwinangun Rukmana
Published: December 2007

This paper describes a feasibility study for pressure maintenance in the E-22 reservoir of the Ardjuna Field, Offshore Northwest Java. Results of a black-oil reservoir simulation study have been used as the basis for evaluation of pressure maintenance project alternatives.

Various operating schemes have been examined for their efficiencies in terms of recovery and cost. Alternatives considered are: 1) continued natural depletion, 2) gas injection, 3) water injection, and 4) simultaneous injection of gas and water. Production is derived from a combination of gas cap expansion, gravity drainage, solution gas drive, and water influx. The study concludes that gas injection into the gas cap will be the most efficient pressure maintenance program. Water injection only and/or simultaneous injection of gas and water would be either less efficient or economically unattractive.
An Experimental Study Of Linear Unsteady State Gas Flow Through Low Permeability Porous Media
Authors: Millheim Keith , Menzie D.E.
Published: December 2007

Publication Rights Reserved

This paper was to be presented at the 40th Annual Fall Meeting of the Society of Petroleum Engineers of AIME, to be held in Denver, Colorado, October 3–6, 1965, and is considered to an abstract of not more than 300 words, with no illustrations, unless the paper is specifically released to the press by the Editor of the Journal of Petroleum Technology or the Executive Secretary. Such abstract elsewhere after publication in the Journal of Petroleum Technology or Society of Petroleum Engineers Journal is granted on request, providing proper credit is given that publication and the original presentation of the paper.

Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

This paper presents an experimental study of linear unsteady state gas flow through a low permeability porous medium. Results of a series of controlled tests indicate that a steady state approximation technique for the solution of linear unsteady state gas flow is the most accurate and convenient method. s tests confirm the validity of using finite difference equations for solving the nonlinear partial differential equation for the unsteady state gas flow. Also the results these tests indicate that the modified solution of the partial differential equation relating slightly compressible fluid flow does not represent gas flow in a low permeability porous medium.

Introduction

The investigation of unsteady state gas flow has been restricted almost entirely to mathematical analysis. Basically, there are three types of solutions which approximate gas flow:

The first method is a modified solution of the differential equation representing slightly compressible fluid flow. Certain critical assumptions are used to force the liquid solutions to exemplify gas flow. For the second type of solution, finite difference equations are used to represent and solve the non-linear partial differential equation for gas flow. The most recent analysis of transient gas flow involves forcing the steady state flow equation for gas to predict pressure decay with time.

Since all three types of analyses are not true solutions to the differential equation relating gas flow in porous media, they are restricted to certain limiting assumptions and methods of calculation. For example, method number one has the limitation that small pressure drawdowns must occur in the reservoir. In the case of low permeability formations, this is almost an impossibility.
A Parametric Evaluation of Steam Followed by Water Process for Heavy and Light Oils
Authors: Huang W S , Hermes C E
Published: December 2007

A commercial reservoir simulator capable of simulating operational changes in a steam flood was used to investigate the effect of steam slug size, water injection temperature, water injection rate and pattern lifting capacity in converting from steam to water injection. Inverted seven-spot and five-spot patterns were used for heavy oils and light oils reservoirs, respectively. The optimum steam slug size which is dependent on the injection, production and reservoir parameters was determined for both the heavy and light oil reservoir cases based on economic studies for realizing the maximum revenue on a project.
A Reliability Approach for Design and Evaluation of Offshore Structures
Authors: Chen Y N , Takla R M , Jan H Y
Published: December 2007

This paper is intended to discuss the basic issues involved in structural reliability in conjunction with a limit state approach for design and analysis of offshore structures. Emphasis will be placed on a systematic semiprobabilistic approach suitable for strength evaluation of major structural elements. Problems arising from quantification of uncertainties of the pertinent random variables, load combination, and in the development of limit state functions involving both ultimate failure and fatigue, will also be discussed.
Design Considerations of Permanently Moored Semi-Submersibles
Authors: Bainbridge C. A.
Published: December 2007

The semi-submersible has been adapted to perform numerous functions offshore unconnected with drilling but still operating as a mobile unit. When used as an early production unit however, it is required to remain on a particular site for several years. The strength and fatigue of one such unit is considered for three different locations in the North Sea. For completeness, several other typical design features have been incorporated into the structure. Existing and proposed fatigue criteria are investigated and the results discussed. The principal conclusion is that major structural modifications will be required if the proposed changes are implemented.
Behaviour of Tension Leg Platform in South China Seas
Authors: Qi Xin-Yuen , Lin Ji-Ru , He Cheng-Yuen , Sun Be-Qi
Published: December 2007

This caper is the first phase report in the investigation of Tension Leg Platform in CSSRC. A series of tests and computational work have been performed for a four column TLP in 256m water depth under the influence of waves.

Attention was paid to investigate the effect of variation of pretension of tether load and pontoon configuration on the behaviour of TLP in waves. Survival condition for the TLP was also investigated, including a case study of leg failure in storm waves.

Results of computations based on 3D potential theory by CRS-WAVE are compared with results of model tests. The applicability of the method is confirmed.
Design And Tank Test Of A Compactly Designed Semi-Submersible Drilling Unit
Authors: Miwa Elichi , Isozaki Yoshio
Published: December 2007

The design water depth of recent jack-up drilling units have remarkably increased and it enables the compact semi-submersible drilling units to compete with these large jack-up rigs economically.

Taking consideration of this trend, we developed a compact semi-submersible drilling unit, named MD-I 02, which has the box type configuration to be different from he conventional semi-sub rigs; and we carried out the computer analysis and the model tank test to confirm the motion characteristics in waves.

As a result, it was clarified that the experimental motion characteristics have a good agreement with the calculated ones and the downtime of the design is almost the same as that for the other large semi-sub rigs in the comparatively moderate seas such as off South East Asia. It was also clarified that it is not possible to apply the added mass coefficient of heaving in infinite fluid to that for such special lower hulls and it is necessary to pay particular attention to it.

Introduction

The design water depth of the recent jack-up type drilling units have remarkably increased and the jack-up rig for 400 ft water depth has been constructed.

The tendency of increase of operating water makes the building cost grow in geometrical progression. In other words, the water depth in such area is too deep for the jack-up rig to operate economically.

So, the operation of the competitive semi-submersible drilling unit with jack-up rig is able to be taken into consideration. However, it is too shallow for the large semi-sub rig to operate economically. It is therefore necessary to develop the compactly designed semi-sub rig which is not achieved by the reduced scale version of large semi-sub rig due to stability and performance.

We have developed the compactly designed semi-submersible drilling unit, to meet the marketability above-mentioned, which has the box type columns and lower hulls.

To confirm the motion characteristics in waves of this compact semi-submersible unit which has a different configuration from the conventional semi-sub, the model tank tests were carried out in the regular and irregular waves.

p. 9–111 p. 9–111
Fire-Resistant Wellhead Equipment for Offshore Platforms
Authors: Williams Michael R.
Published: December 2007

A new generation of fire-resistant wellhead equipment has been developed for offshore platforms. This paper presents the design concepts and principles of operation of this new equipment, and it describes the engineering approach taken during its development.

These new wellheads and Christmas trees have survived numerous laboratory fire tests which simulated offshore platform fire conditions. No leakage was permissible during the test burns nor during the subsequent cooldown periods. The laboratory fire test results confirmed the performance predicted by computer Finite Element Analysis and verified the design procedures employed.

This new fire resistant wellhead equipment promises to significantly reduce the fire hazard associated with the production of oil and gas from offshore platform wells.
Arun Field Tubular Performance, Quality Control and Operating Experience
Authors: Ridwan Amir , Hull K. B.
Published: December 2007

This paper discusses the experience of and the solution to problems which have arisen concerning tubular products used by Mobil Oil Indonesia, Inc in Arun Field gas well completions.

Mobil Oil Indonesia has developed and implemented an intensive Tubular Quality Control Program to maximize the quality and integrity of the tubular products which are subjected to the extreme conditions of this prolific gas field.

The Tubular Quality Control Program which monitors the specified tubular quality from the steel mill to the rig floor has successfully maintained safe and dependable well operations with higher tubing integrity.
Gas Disposal Aboard A Floating Production Facility
Authors: Otten Lawrence E. , Scoles Lee R.
Published: December 2007

The Cadlao Floating Production, Storage and Offloading (FPSO) Facility has on board equipment to separate the oil, water and gas produced from two subsea wells. The produced natural gas is used to fire the original ship's steam boilers and excess gas is disposed of through an enclosed vertical flare.

The Cadlao produced gas contains up to 6000 ppm H2S and added safeguards were necessary for burning the sour gas in the boilers and in the flare stack.

Gas compression equipment installed to allow gas injection into the well-streams to reduce the hydrostatic head of the produced fluid column has not yet been used.

BOILER FUEL

The converted tanker was equipped with two 50000 kg/hour standard marine boilers. The boiler room equipment was completely redundant to insure steam for vessel maneuverability at all times. The converted vessel does not require steam for maneuverability and with a 750 kw diesel standby generator, and a 330 kw emergency diesel generator in addition to the two original 700 kw steam-driven generators can be without steam power to extended periods of time.

The FPSO boilers operate in two modes:producing operations where the distillation plant and one 750 kw steam-turbine generator are in use oroffloading when the steam-driven cargo and stripping pumps ore also added to the boiler load.

Either boiler has adequate capacity for both load conditions, and only one boiler is fired at a time. The boiler not in use is alternated each month to assure continued proper operation of both boiler systems.

All fuel gas lines are made up of concentric piping up to the individual boiler face. At the boiler face, the fuel gas controls and piping are enclosed in an exhaust hood which will exhaust any sour fuel gas leaked from the boiler face piping/controls (see Figure 2). The pressure reduction from the exhaust fans at this location is sufficient to overcome the tendency of H2S gases to sink to the lower levels of the engine room. The exhaust fan failure and HAS and explosive level located in the exhaust hood are interlocked with the boiler fail-safe shut-dawn system. Other H2S sensors are strategically placed about the engine room.

p. 11–61 p. 11–61
Development Drilling Problems Offshore Malaysia
Authors: Osman Mohamed Nor , Maung Mya
Published: December 2007

This paper highlights the major drilling problems encountered in the field development programmes offshore Malaysia from 1978 to mid-1983. The major problems identified were pipe sticking which was common in all the areas and top hole drilling problems encountered in a few fields offshore Sabah and Sarawak. Generally, the problems were related to drilling deviated wells through the soft and unconsolidated formations common in this region. Preventive measures employed by the Contractors have been effective in overcoming these problems in the later years of the period under consideration.
Cost Effective and Maintenance Effective Design for Geothermal Power Plants
Authors: Bouma John
Published: December 2007

This paper encompasses a number of considerations that can be made for the design and construction of a geothermal power plant. The considerations consist of both practical approaches and economic trade-offs of design concepts. Throughout the design, simplicity is the key note in the shaping of this geothermal power plant.

During the course of the design, the elements that initially appear problematic are turned around by means of innovative design concepts, resulting in an effective and economical overall design.

This paper also discusses the impact of climate and elevation on the construction of the plant. The relation of starting construction and the season in which construction is started, is critical.

The use of easy maintainable auxiliary equipment is considered by tailoring the auxiliaries to the available overhauling facilities of the country for which the plant is designed.
Aerated Fluid Drilling Observations in Geothermal Operation in Luzon, Philippines
Authors: Rizo T M , Cuenca A P
Published: December 2007

This paper compliments the potential use of aerated fluid drilling in oil-gas operation of which the techniques in application was further extended to geothermal energy drilling.

Compared with the use of conventional mud in both oil-gas and geothermal drilling operation, the benefits of aerated fluid cannot be denied. However, the developed utilization of blind drilling in geothermal operation in Luzon, Philippines were observed to be more beneficial.

This paper highlights the incremental costs involved in using aerated fluid compared with blind drilling with water in geothermal operation within the 8½" hole interval when total lost circulation zones are encountered.
Review of the Mechanical Design Requirements for Offshore Pedestal Cranes
Authors: Alexander P E , Wong W
Published: December 2007

Modern design philosophies for offshore cranes require the structural components to be designed for the dynamic loadings experienced in the offshore environment. If these predicted impact loads are applied to the relevant winch load-paths, then the ccmponents in those load-paths can be appropriately designed. Specifications do not at present, require the operator to predict at the enquiry stage, the service duty and load spectrums for the crane. When these are specified by the operator, the designer is able to apply appropriate stress levels to the components to attain the required crane life.
H2S Safety Aboard an Offshore Production Facility Handling Crude Oil and Associated Sour Natural Gas
Authors: Devries Peter , Scoles Lee R
Published: December 2007

This paper describes the safety system and training for personnel on board the floating production storage and offloading (FPSO II) currently working in the Cadlao Field, offshore Palawan in the Philippine Islands. (See Figure 1). The crude oil being produced has weiistreσm hydrogen sulfide concentrations up to 6000 PPM. Concentrations of hydrogen sulfide at 700 PPM or higher can be immediately dangerous to life and every effort must be made to ensure personnel safety.
Evolution In The Natural Gas Processing Plant
Authors: Barber Harold W.
Published: December 2007

We view with appreciation and amasement the changes that have come about in the facilities that are available for our everyday use. For instance, not the tremendous improvement in home communication facilities. A very few years ago we listened to the amusing antios of "Fibber McGee and Molly" on the radio, or Bill Stern's exciting description of a football game. Now we watch in brilliant color on our television set as actors perform, and have 50-yard-line seats at football games. Word meanings have made changes also. In my early years a dishwasher was a domestic helper or a "pearl diver" in a restaurant, but to my children it is a machine that sits under the kitchen counter and ashes the dishes while the family takes a walk to get in the exercise prescribed by the doctor. The Natural Gas Processing Industry has made similar changes, but those of us closely connected to it tend to minimise or overlook our improvements. The purpose of this article ihe equation assumes that the properties of the fluids in both the hydrocarbon zone and the water zone are the same. Solutions of the same differential equation, but with many different boundary conditions, have been described by Carslaw and Jaeger in their book.
Piper Field: Operational Aspects of Drilling/Completions/Workovers/Data Acquisition And Well Performance
Authors: King Paul A.
Published: December 2007

This paper presents a brief insight into the operational aspects of the development of Occidental's Piper field. The paper discusses all operational aspects of the development programme commencing with the drilling and initial completion phase, then moving into a discussion of the various types of workover which have taken place to date and concluding with a section reviewing the data gathering programme that has been running throughout the life of the field. This final section also shows the degree of accuracy that has been attained in matching predicted to actual well performance.
Planning and Drilling a 24,325-Ft Well in Southwest Oklahoma's Anadarko Basin
Authors: Welch E. R.
Published: December 2007

Texaco drilled a well in southwest central Oklahoma which reached a total depth of 24,325 feet. This test presented a unique challenge both in planning and implementing the drilling program. The design, techniques, and practices followed to attain an optimum drilling program are presented.
A Decade of U.S. Drilling … Trends, Characteristics, Outlook
Authors: Dougherty Tom
Published: December 2007

Despite the downturn in drilling attendant upon price uncertainties which surfaced in late 1981, completions recorded in the U.S. in 1983 stood second only to the 1982 total.

Deep drilling declined more sharply in relation to 1982. And, pure exploration… new field wildcats drilled… declined. The new field wildcat success rate was less than 17 percent, down from a four year average of more than 18.5 percent.

Oil wells, as a percentage of total completions, increased. Gas wells, however, fell back to 18 percent, the lowest level in a decade.

Crude and condensate production remained about level with prior years since drilling reversed the early Seventies downward trend in production. Gas production declined, not because of ability to produce, but because of decline in market.

In the first four years of the Eighties, some 306,000 wells were completed. This is approximately 10 percent of all domestic drilling to date.

Exploration below 15,000 feet over the four years has had a success ratio of 14 percent demonstrating the additional potential remaining to be exploited under proper economic conditions.

Demand will increase through most of the remainder of the century, assuring upward progression of prices and, consequently, continued high levels of drilling. This is essential to the welfare of the nation, since in recent years reserve replacements have not equalled withdrawals.

In 1984 an average of about 2,600 rotary rigs will be active and it is expected that approximately 70,000 wells will be drilled in the United States.
CO2 Corrosion in the Anadarko Basin
Authors: Browning D. R.
Published: December 2007

Some high pressure, temperature and volume gas wells located in the Anadarko Basin area of Washita, Beckham, and Roger Mills counties of Oklahoma have demonstrated in several cases severe corrosion rates which has led to surface equipment and tubular failures. This paper deals primarily with the El Paso Exploration Company's approach to the corrosion problem in producing gas wells.

A basic theory on the mechanism of CO2 corrosion and the identification of this type of corrosion will be presented to insure a general understanding of this type of corrosion. A discussion on the detection and monitoring system used with comparison of water and gas analysis, visual inspections, ultrasonic thickness measurements and coupon installation. The procedures which determines whether or not a well may require corrosion treating, along with the method by which the wells are treated, and the amount of protection which can be expected from individual treatments. Some specific problems and personal observations will be presented on the corrosion that has been found in the field which may be utilized as a guide or a better indication that a corrosive environment exists. A discussion on corrosion and a corrosion program as it affects economic, environmental and personal safety aspects should a failure occur is also presented.
Drilling: A Long Way To Go
Authors: Holley G. T.
Published: December 2007

These are difficult times in the oil and gas industry. With the changes currently taking place in daily operations, drilling contractors and service companies have to remain flexible enough to adapt and survive.

The period from 1980-1982 saw the industry become cost inefficient. No one segment of the industry could be blamed for the inefficiency. All were strapped with more work than they could do and were burdened by a shortage of qualified people.

Now with the shakeout slowing, the industry can regroup and reevaluate what has been learned during the recent period of unprecedented growth and activity.

With the tight money situation, operators will be most concerned about drilling good prospects and keeping costs reasonable. The drilling contractor's and service companies' prime goal will be to survive. Their emphasis will be put on increasing rates and hoping for a quick return to profitability or at least a positive cash flow.
Application of Foamed Portland Cement to Deep Well Conditions in West Texas
Authors: Bozich M. P. , Montman R. C. , Harms W. M.
Published: December 2007

Inherent in all casing programs there exists one area of special concern, and in deep well drilling that usually involves the setting of a long intermediate string of casing. The presence of weak, pressure intolerant lost circulation zones often makes cementing of the intermediate string the most difficult and expensive cementing operation encountered during completion of the well.

The use of an economically attractive and field proven cementing technique has resulted in more predictable results than previously established methods. The application of foam cement at slurry densities equivalent to or less than the drilling fluid weight has resulted in placement of quality cement higher above frail zones than previously possible in a single-stage cementing operation.

Case histories, economic analysis, physical properties and developmental background of foam cementing as applied to deep well drilling will be presented.