bluuebunny/crossref_metadata_2025 huggingface dataset:
Mud Flow Compensation System for Floating Vessels
Authors: Hatleskog J. T.
Published: December 2007

On a floating vessel or rig, heave can cause severe disturbances in the returning mud flow from the marine riser into the Flow Line. This effect is due to the changing height of the outflow point of the marine riser with respect to the sea bed. Thus the heave can be considered a volumetric flow disturbance, which for short intervals in the heave cycle, can be several times greater than the pump flow making accurate measurement very difficult.

Roll and pitch can also have a disturbance effect the flow in the Flow lines, this depends on the length and the fall in the Flow Line and the way the levels in the tanks and pits are measured.

These environmental effects can at times obscure and make the task of measuring the flow even more difficult than otherwise. The common method of obtaining a sufficiently accurate measure is either by averaging over longer periods or to revert to static measurements. That is, to stop the pumping process which means that it is the dynamic content of the measurement that tend to be lost.

Unfortunately, it is this absence of precise dynamic content in the flow measurement that can make cross correlation techniques, using the heave information to predict the flow development, rather uncertain.

This paper outlines a prototype Flow Compensator System (FCS) with the objective to minimise the effect of heave and to provide an optimum measurement point of flow in and out of the well.

The paper goes on to discuss the initial design requirements, installation, field operation and performance of the prototype equipment, outlining the lessons learnt and their influence on the development of a FCS for general use.
Biodegradable Muds: An Attractive Answer to Environmental Legislations Around Offshore Drilling
Authors: Degouy Didier , Argillier J-F. , Demoulin André , Velghe Firmin
Published: December 2007

For many years, oil based muds have shown proof of efficiency towards hostile drilling cases especially water – sensitive shales or high temperature wells. However, their use is subjected to more and more constraints due to the fast evolution of environmental legislations. One of the possibilities to avoid this problem while keeping the advantages of oil muds consists in substituting mineral oils by biodegradable vegetable oils such as fatty acid esters.

The esters used in these new oil-based muds have an aerobic biodegradability of more than 85 % after 4 weeks and an anaerobic biodegradability of more than 60 % after 2 months.

An original formulation has been developed, presenting very good properties up to 140°C. Its performances are based on a properly choice of ester quality, emulsifying system and additives types, and on a severe control of lime concentration to avoid any risks of ester hydrolysis in conjunction to pH and temperature.

Its behavior has been studied under bottomhole conditions, using an home made HT/HP flow loop, during aging. Contamination tests demonstrated the ability of ester-based muds to resist to possible contaminations i.e., sea water, drilled solids, cements during the drilling process.
Successful Completion Operations on Ravenspurn North Development
Authors: Prise G. J. , Stewart D. R. , Bird T. M. , Holland Brian , Wilson W. W.
Published: December 2007

This paper presents an overview of how the Completion performance on Ravenspurn North Development (RND) has been dramatically improved resulting in significant savings in well costs. With reference to performance statistics, four key aspects are reviewed. These are the Completions Team, the Design Optimisation, the Procedural Optimisation and the Performance Optimisation.
The P/12 Compression Operating Lease Agreement: A Tailored and Flexible Approach to Capital Equipment Financing
Authors: Zoon R. B.
Published: December 2007

Mobil Producing Netherlands, Inc. as Operator for the P/12 Group of Dutch Offshore block P/12 recently concluded an Operating Lease Agreement for the supply of a compression module with the Dutch engineering contractor ABB Global Engineering b.v. Because of the envisaged short term use of the equipment, leasing of the complete module proved to be a cost effective alternative to purchasing. Leasing presented a tailored and flexible approach to capital equipment financing.

The module is compressing gas coming from two small gas fields in Dutch offshore block P/12 with total reserves of some 150 Bscf. The 250 ton module was installed on the Mobil operated P/6-A gas production platform during fall of 1992. The module includes a 4 MW single stage compressor skid and is capable of compressing 100 MMscf/d of gas from a minimum suction pressure of 500 psi to pipeline pressure of 1500 psi.

The lease agreement was constructed as an Engineering, Procurement, Installation and Commissioning (EPIC) type contract and included detailed egineering, procurement and supply of all equipment, module fabrication, single lift installation, and hook-up and commissioning. One main contractor had full responsibility for getting the module built, installed and operational.

The lease has a three year base term, after which the term can be extended on a yearly basis, or the lease can be terminated by either purchasing the module for a pre-determined price, or by returning the module to the owner. The lease is the first of its kind in the North Sea area.

The financial and economic benefits of the lease concept are explained, and the roles and responsibilities of the different parties involved in the lease agreement are discussed.
The Angus Field: Development to Abandonment
Authors: Morel E H , Scott G C
Published: December 2007

The Angus field, with 7.3 MMstb original expected oil reserves is small by UK North Sea standards. It was discovered in 1983, but was left undeveloped until 1990 when a two well appraisal programme demonstrated that the field could be economically produced from these wells using the Petrojarl 1 floating production and storage offtake vessel, with tanker offloading. This novel arrangement allowed the project to be developed rapidly from appraisal, minimised capital investment, and financial risk, to the Angus partnership.

The performance of the field surpassed expectations, with ultimate recovery of 10.6 MMstb being recovered in 18 months. This, combined with the excellent operating performance of the Petrojarl, ensured the excellent financial performance of the development, and has demonstrated one way small isolated oil accumulations can be profitably exploited in offshore areas such as the UKCS.

This paper describes the Angus development, and also some of the technical and management problems caused by the relatively short field life. These included measures to reduce risk, and having to choose the field abandonment date while still on plateau.

The paper also discusses Angus profitability, and the effect UK tax changes will have on future exploration of small prospects.
F3-FB Production Platform
Authors: Boon Wilbert , Spiekerman Joop , Berkhoff Jo
Published: December 2007

This paper describes the design, fabrication and installation of the gas and oil production facilities for the "Nederlandse Aardolie Maatschappij B.V." (NAM) F3-FB complex on the Dutch continental shelf of the North Sea. NAM carried out the basic conceptual design for the complex and prepared the execution plan for the project development. FLUOR DANIEL B.V. was chosen to be the engineering contractor for the topsides and started in conjunction with NAM to develop the Project Specification followed by the detailed design for the F3-FB complex. This paper is prepared by FLUOR DANIEL B.V. and presents an overview on the technical aspects of the F3-FB complex. The reader should realize that a number of aspects presented here, where developed and defined by NAM before authors of this paper where involved in the project, but are added for completeness of the paper. The paper is intended to be a structural presentation of the design, fabrication and installation of the production platform deck, but a number of other interesting developments are presented.
GYDA: Recovery of Difficult Reserves by Flexible Development and Conventional Reservoir Management
Authors: Rothwell N. R. , Sørensen Astrid , Peak J. L. , Byskov Kristian , McKean T. A. M.
Published: December 2007

Gyda is a 200MMstb field, located in the North Sea Central Trough, offshore Norway. The field was discovered in 1980, and first oil was produced in 1990. It is one of the deepest, hottest and poorest quality oilfields in the North Sea. The structurally complex field contains three different fluid types, and the crude is asphaltene rich. The shallow marine sandstone reservoir is gently dipping, wedge-shaped, with an oil column of 500m. The field receives no aquifer support and is being developed by waterflood. The connate water/injection water mix has a severe scaling tendency.

Development of the field is set against a background of tight cost control within the industry generally, and within the Operating company in particular. With six wells drilled per year, a current offtake rate of 70Mstbpd, and areas of the field showing early mature performance, the challenge is to maintain production whilst keeping costs low. The development is therefore managed by maintaining maximum flexibility in drilling locations, sequence and well use, by use of appropriate technology, and by the innovative use of conventional techniques to exploit the field's characteristics.

This paper describes: 1. reservoir complexity; 2. the technologies employed to meet the reservoir management challenges; 3. development philosophy; 4. field management history; and 5. value generation.
The Influence of Interfacial Tension on Liquid Mobility in Gas Condensate Systems
Authors: Ali J. K. , Butler Sarah , Allen Lilas , Wardle Peter
Published: December 2007

Coreflooding experiments have been performed using 1 metre long, sandstone cores and a synthetic, six component (C1, C2, C3, C5, C8 and C16) gas condensate fluid, with a dewpoint close to 4,500 psia. The efficiency of equilibrium gas injection for the mobilisation of liquid condensate has been examined under both high and low interfacial tension (IFT) conditions. The volume of liquid recovered and the composition of both phases have been monitored throughout each experiment and the results used to validate a compositional simulator.

Under conditions of maximum liquid dropout and high IFT (σ ≈ .92 mN/m), an average of 6.5% volume of liquid condensate was mobilised in an equilibrium gas injection in a horizontal core, resulting in reduced recovery of the heavier components of the fluid. An improved recovery of 17.2% was obtained in the vertical injection.

Under conditions of low IFT (σ ≈ .04 mN/m) however, 24.1% of the liquid was recovered during injection in a horizontal core and 51.6% of liquid was recovered with vertical injection, giving a much increased yield of the heavier ends.

The recovery efficiency in a straight depletion on a horizontal core to abandonment pressure averaged 18.8%. This is much lower than for the low tension gas injection.

These results are in agreement with other recent studies concerning the influence of IFT and the effects of gravity on gas condensate flow.
Active Ultrasonic Monitoring of Laboratory-Scale Hydraulic Fracturing Experiments: Numerical Modelling vs. Experiment
Authors: Savic Milos , Cockram M. J. , Ziolkowski A. M.
Published: December 2007

A state-of-the-art data acquisition system has been built at Delft University of Technology which allows rapid acquisition of reflection, pulse-echo and transmission records during hydraulic fracturing experiments on cement or rock samples. Recent experiments show that it is possible to observe clear acoustic signals from a hydraulic fracture that is very thin compared to the wavelength of the illuminating elastic waves. Imaging with reflected compressional signals produces a clear image of the fracture. The signals diffracted from the fracture tip enable accurate calculation of the radius-time diagram. The variation of the amplitude of the compressional waves transmitted through the fracture is mainly caused by the interference between transmitted and scattered wave-fields. However, a subtle difference between numerically calculated and observed wavefields suggest that it might be possible to infer the length of the non-penetrated zone. The material type has a major influence on the fracture visibility after shut-in.
Expert System for Selection of Optimum Artificial Lift Method
Authors: Espin D. A. , Gasbarri S. , Chacin J. E.
Published: December 2007

Artificial lift is used worldwide in approximately 85% of the wells, thus its impact in overall efficiency and profitability of production operations can not be overemphasized. Selection of a particular lift method for a given application is carried out, to a large extent, by production engineers utilizing the method more readily available to them both in terms of their past experience and current access to knowledge and technology. It has been recognized for a long time, that this is a shortcoming of most engineering disciplines and results, more often than not, in sub-optimal designs. Expert systems can help engineers in quickly selecting, from updated technology, the best options available to them for the problem at hand.

The work presented here describes knowledge gathering and coding techniques, general program structure, program validation runs, and field verification of SEDLA, an expert system developed to help in the selection of the best lift method for a well or group of wells.1
Optimizing Gas injection into Naturally Fractured Reservoirs
Authors: Qasem F. H. , Ershaghi I.
Published: December 2007

This study examines the necessity of pressure maintenance by immiscible gas injection into solution gas naturally fractured reservoirs. Gas injection is shown to be a controlling tactor to minimize resaturalion of down structure matrix blocks. Spatial variability in matrix properties influences the overall recovery. Realization of recovery optimization amid spatial variability is illustrated for some idealized reservoir structures.
Producing Extra Heavy Oil from the Orinoco Belt by Electrical Submersible Pumping System - A Pilot Test
Authors: Gonzalez R. , Reina M.
Published: December 2007

Heavy and extra-heavy oils have been traditionally produced using sucker rod pumping. However, this production method is inefficient, highly energy consuming, and the useful life of the equipment is short. Therefore, other methods of artificial lift have to be evaluated, in order to exploit the heavy oil reserves more efficiently and economically.

In this paper, the results of a pilot test using an electrical submergible pump to produce extra-heavy oil (9.2 °API) in the Orinoco Belt, Eastern Venezuela, are presented. The maximum production rate obtained was 1,170 BOPD (186 M3/D), which is 700 BOPD (111 M3/D) higher than the maximum rate obtained with sucker rod pumping in the same well. No diluent was used in this particular test.

The pumping efficiency obtained (37.7%) indicates that with a higher capacity pump, production rates of up to 2,000 BOPD (318 M3/D), without the use of diluent, can be achieved.
3-D Analytical Model for Displacement of Oil Using Horizontal Wells
Authors: Bedrikovetsky P. G. , Magarshak T. O. , Shapiro A. A.
Published: December 2007

The purpose of this work is to develop an analytical model that produces results close to numerical 3D model for miscible displacement using horizontal wells. An analytical model has been developed for three-dimensional flow in system of horizontal wells. Different systems of horizontal injection and producing wells are discussed. The analytical model includes 3D picture of flow between injection and producing wells, bottom and top of the a reservoir, different viscosities of displaced and injected fluids. The model automatically calculates location of displacement front, breakthrough time and composition of fluid produced. It allows to compare sweep efficiency with different locations of injection and producing wells.

A computer floppy disk for 386 PC is available that contains software with PASCAL programs of the model, and sample data files. Files listing the results with graphical representation are also included.
A Study of Sensitivity of Relevant Parameters to Predict Sand Production
Authors: Ghalambor A. , Hayatdavoudi A. , Koliba R. J.
Published: December 2007

A sensitivity analysis was carried out during a course of study to develop a model for predicting sand production from gulf coast gas wells which produce free water. A multiple linear regression analysis was used to incorporate data from producing gas wells and log derived properties of reservoir rock in a usuable model. This model fits field data of water producing gas wells. It will be a risky proposition to analyze each individual parameter related to sand production by itself when designing sand control measures. The study shows that the combined effects of these parameters are making a significant contribution in the process. The results indicate that: (1) the volume of water is not correlatable, but the presence of free-water (non condensed from gas phase) increases the sanding tendencies of most gas wells; (2) as a reservoir depletes, its tendency to produce sand increases; (3) efforts to reduce sanding should be directed toward reducing the drawdown across the completion; and (4) many of the log derived parameters that show merit in correlating dry gas wells have no value in water producing gas wells.

When the optimum decision concerning gas production rate and the need for sand control can be made at the time of initial completion, more profit can be realized from the project.
Drilling String Improvement in Horizontal Wells in Neuquen and Mendoza Basin
Authors: Cagnolatti E. F.
Published: December 2007

This paper describes our experience and the analysis done in the desing of the drill string of 18 horizontal wells drilled in Neuquén and Mendoza basin, Argentina. It also refers to heavy wate, drill pipe and drillcollars distribution in horizontal, curved and vertical sections; caliper analysis during curved section drilling and at the end of the well in terms of drilling days; buckling effect in horizontal wells; and the application of a torque and drag program.
The EROS (Earth Resources Observation Satellite) Program Of The Department Of The Interior
Authors: Fischer William A.
Published: December 2007

This paper was prepared for the 44th Annual Fall Meeting of the of the Society of Petroleum Engineers of AIME, to be held in Denver, Colo., Sept. 28-Oct. 1, 1969. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal, provided agreement to give proper credit is made.

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.

The EROS (Earth Resources Observation Satellite) Program of the Department of the Interior is a program to utilize data collected from aircraft and spacecraft for practical resources purposes. Using randomly practical resources purposes. Using randomly collected data from Apollo, Gemini and Mercury space flights, the U.S. Geological Survey has compiled photo mosaics that are map-like in quality of over 1,000,000 square miles of the earth's surface. Using these maps as bases, and the color "space" photos for interpretation, the Geological Survey scientists have prepared:

a geologic terrain map of the prepared: a geologic terrain map of the southwest United States (essentially a soils-association map), and a land-use planning map of the same region, a tectonic map, and soon will complete a land-use map of the area.

Of significance is the "ability" of space images to peer far beneath the waters of the ocean, thereby, holding promise for increasing the efficiency of resources studies of nearshore areas.

Detailed performance specifications have been furnished to NASA, identifying the type of data that would be the greatest of utility to the Department of the Interior. These specifications have been incorporated into the design of the proposed Earth Resources Technology Satellite NASA expects to launch in late 1971 or early 1972.

TEXT

There is great need for new approaches to resources exploration and management. Technological growth and expanding population combine to create an almost insatiable appetite for raw materials, energy, and food. The production and consumption of these, in turn, production and consumption of these, in turn, places increasing stress on our environmenta places increasing stress on our environmenta stress now so severe as to seriously concern both government and the public. There are reasons to believe that these concerns are justified, for example, it is estimated that by the year 2000 much of the waters of our streams will be used to cool our needed energy plants. The effect of such masses of warm water on our environment may be beneficial or detrimental.
Drilling Optimization Using Drilling Data and Available Technology
Authors: Rampersad P. R. , Hareland G. , Boonyapaluk P.
Published: December 2007

This paper demonstrates how information obtained while drilling an oil or gas well, is utilized to optimize drilling costs for upcoming wells in the same field by creating a Geological Drilling Log (GDL). The GDL is created by using drilling models specific to the bits used for individual intervals to generate a formation profile of properties for the entire section drilled on a foot by foot basis. The simulation and optimization are used in the field with the GDL to properly select bits (Tricone or Natural Diamond) and operating conditions for the lowest cost per foot.

The concept of a learning curve is utilized by conducting a number of simulations using the GDL, so that the optimum drilling parameters are obtained. The approach to drilling optimization using a simulator and a GDL in this study showed a substantial reduction in drilling cost. The drilling models used in this study are capable of accurately simulating the drilling of a well and reproducing realistic Rates of Penetration (ROPs).
Characterization of Compressible Reservoirs Using Histories of Well Pressure, Rate and Water-Oil Ratio
Authors: Asheim H.
Published: December 2007

Automatic history matching of finite difference reservoir simulators has been extended to simultaneous (2-phase) flow of water and oil. This results In much Improved parameter matching capability. The method has been tested on cases of one-dimensional core flooding and flooding of two-dimensional reservoirs.
Modeling and Prevention of Asphaltene and Other Heavy Organic Deposition in Oil Wells
Authors: Mansoori G. Ali
Published: December 2007

Well-head production of petroleum can be significantly affected by flocculation, deposition, and plugging of asphaltene, paraffin /wax, and/or diamondoid inside the well. The economic implications of such a formation damage are tremendous. In this paper a comprehensive mechanism and predictive model for such compounds in the oil wells is presented. This model is based on the macromolecular theory of polydisperse polymer and colloidal solutions, kinetics of aggregation, electrokinetic transport phenomena, and phase behavior of multicomponent mixtures.

One question of interest in the oil industry is "when" and "how much" heavy organics will flocculate out under certain conditions. Since a petroleum crude generally consists of a mixture of hydrocarbons and heavy organics it may be necessary to look at this problem from a more fundamental point of view than it has been the practice in the past. In this paper the author presents the cause and effect mechanisms of such depositions and introduces mathematical models to be used for preventive measures in various cases of petroleum production, transportation, and processing.

With the application of the proposed models a number of predictive case studies are made. It is shown that with proper plannings in the production scheme, consideration of the characteristics of the producing petroleum, injection fluid, well casing, and the reservoir it is possible to choose a formation-damage-free production scheme.
Underbalanced Drilling of Horizontal Wells: Does It Really Eliminate Formation Damage?
Authors: Bennion D. B. , Thomas F. B.
Published: December 2007

Recently, underbalanced drilling has been utilized as a technique to minimize invasive formation damage in both horizontal and vertical wells. While it is widely accepted that underbalanced drilling greatly reduces the propensity for formation damage, particularly with respect to the potential for whole mud losses and invasion of mud solids, the potential for formation damage still exists in situations where the original saturation in the reservoir (either hydrocarbon or water), is less than the irreducible saturation of the phase utilized in drilling and the capillary pressure and wettability characteristics can cause spontaneous imbibition. This often occurs when drilling in an underbalanced mode in low permeability gas reservoirs that have abnormally low initial water saturations. Although fluid flow is occurring from the formation, circulating drilling fluids are in dynamic continual contact with the formation face. At abnormally low initial saturations, there exists the ability for strong, spontaneous imbibition effects which can, in some situations, counteract pressures that are far greater than the apparent underbalance pressure occurring during the drilling process. If the formation contains potentially sensitive clay materials, deflocculatable fines, the potential for emulsions or permeability reductions due to aqueous phase trapping, these phenomena could possibly occur and reduce permeability. The fact that a stable filter cake is not developed during underbalanced drilling, due to continual inflow from the formation face, could increase the severity of these phenomena as a fully exposed formation face which remains unshielded by any type of bridging or sealing filter cake is exposed for potential imbibition effects at all times. In addition, if any overbalanced pulses occur during drilling or completion, the potential for severe and damaging fluid and solids losses to the unprotected formation can be significant. This paper documents potential damage scenarios based on the results of specific laboratory tests and reviews new techniques designed to evaluate and pre-screen underbalanced drilling operations prior to costly implementation in the field.
Alteration of Reservoir Rock Wettability and Its Flow Properties Caused by Oil-Based and Water-Based Drilling Muds
Authors: Sanner D. O. , Azar J. J.
Published: December 2007

A core study was conducted to investigate the return-permeability and changes in the irreducible water saturation in Sandstone and Carbonate cores, when exposed to filtrate from actual oil-based and water-based drilling mud.

Results indicate that the oil-based filtrate contains sufficient oil wetting surfactants and emulsifiers to reverse the wettability of rock surfaces from water wet to oil wet. The oil wet rock surface in the low permeability matrix, reduced the effective oil permeability drastically. In the high permeability matrix, the change in wettability to an oil wet system reduced the irreducible water saturation, resulting in an increase in the effective oil permeability. This effect was observed for Sandstone as well as the carbonate cores (1).

Clay swelling, dispersion and ion exchange combined with water blockage are believed to control the changes in flow properties for the Sandstone core samples. The introduction of colloidal particles and the dissolving of calcite are believed to be the mechanisms controlling the changes observed in the flow properties for the carbonate cores (1).
Step-Pressure Test for Stress-Sensitive Permeability Determination
Authors: Economides M. J. , Buchsteiner Hubert , Leoben Mining U. , Warpinski N. R.
Published: December 2007

A step-pressure test is introduced to evaluate stress sensitivity of the reservoir permeability. In this test the transient rate is measured against time at constant flowing pressures. The test is repeated several times at different pressure levels. The controlling permeabilities, thus calculated, are stress-sensitive within the radius of investigation.
The Effect of Crude Oil Composition on Aqueous Phase-Rock Interaction: Implications on Formation Damage in the Enhanced Recovery of Heavy Oil
Authors: Manrique E. J. , Villalba Marlene , Mendez Zuleyka , Der Sarkissian Juan
Published: December 2007

Aqueous fluids are shown to interact strongly with sandstones at elevated temperatures and have been reported to produce formation damage related to dissolution and precipitation of minerals. But the presence of crude oil, along with the crude-oil type, may affect the rate and amount of this chemical interaction. Additionally, if the crude oil has small but important amounts of organics acids (> 2 mg KOH/g oil), these can react with the alkaline solutions to produce "in-situ" surface active compounds. These surfactants can be adsorbed on rock surfaces and alter the wettability of reservoirs rocks.

An experimental study was conducted to examine and predict the effect of crude oil composition on in-situ surfactant production and to evaluate the potential formation damage on friable sandstones of heavy crude oil reservoir — Western Venezuela. The tests were carried out at relatively high temperatures (200° C) of system mineral/crude oil/aqueous fluids and the system crude oil/aqueous fluids. Minerals, crude oils and solutions were analyzed by different analytical techniques before and after reaction took place.

The results from this investigation showed that pH and presence and type of crude oil affect the dissolution of minerals. Experimental evidence suggested a strong reduction of the interfacial tension after the reaction of acidic crude oils with alkaline solutions. NMR, IR and GC/MS analysis indicate the presence of organic compounds in the aqueous phase.
Interpretation of Matrix Acidizing Treatments Using a Continuously Monitored Skin Factor
Authors: Behenna F. R.
Published: December 2007

Several techniques for the real-time evaluation of matrix acidizing have been presented over the years.1,2,3 All rely on the calculation of the skin factor of the formation during the course of the treatment as the indicator for treatment effectiveness.

Two general approaches are currently used for calculating the skin factor of a well during a matrix acidizing treatment. The first assumes that a steady-state flow regime is in effect during injection while the second uses a pressure transient solution to calculate the skin factor during the treatment and assumes the well is in an infinite-acting transient flow regime. Comparisons of both calculation methods will be presented in this paper as will the advantages and limitations common to both methods. Also presented are two field case histories in which a pressure transient solution was used to continuously monitor the skin factor during the treatments. These case histories show in detail the effect of the different fluid stages injected during the treatments, including the effect of diversion stages. The concept of using the derivative of the skin factor with respect to time to track the rate of damage removal during acid injection or the rate of skin factor increase during diversion stage injection is also introduced.
Evaluation of Blast Furnace Slag Slurries for Oilfield Application
Authors: Benge O. G. , Webster W. W.
Published: December 2007

This paper presents an investigation of several slurries using field and laboratory prepared drilling fluids solidified with Blast Furnace Slag. The data presented includes base mud properties, final slurry composition, and slurry properties. This investigation includes measurements of the common properties of thickening time, compressive strength, free water, etc. It also includes an evaluation of the bulk shrinkage of the set material, shear bond, etc., as well as rheological compatibility studies of the finished slurries with the base muds. These additional tests are considered critical in the potential application of this process under field conditions. Results of large scale bond log tests are included.

One of the main benefits from any mud solidification process is the reduction in the environmental impact. The benefit is due solely to the reduction of the volume of mud disposal requirements. Due to the dilution requirements of the mud for the incorporation of the Blast Furnace Slag, the actual volume of mud that can be "saved" from disposal may be considerably less than that reported. This study evaluates the actual reductions in disposal volumes while accounting for the dilution volumes. Economic comparisons from field operations are included as well as a theoretical comparison for zero discharge areas like Mobile Bay. Operational considerations and the economics of required mud isolation and storage are reviewed.

From the laboratory data evaluated, environmental, and economic evaluations, it is apparent the use of Blast Furnace Slag slurries for oil field applications must be carefully evaluated on a per case basis. While the process may be a viable mud solidification process, the replacement of Portland cement by this material may compromise some properties considered essential in a cementing operation.
Application of Innovative Extended Reach and Horizontal Drilling Technology in Oilfield Development
Authors: Bell R. A. , Hinkel R. M. , Bunyak M. J. , Payne J. D. , Hood J. L.
Published: December 2007

Since the mid-1980's, key extended reach and horizontal drilling and completion technology has been successfully applied worldwide to improve offshore oil field developments. The prudent application of this technology has resulted in: extended field drainage radii, increased production rates and ultimate field recovery, improved reservoir management, a reduction in required platforms and well counts, improved field economics, new and patented completion tools and technology, and world drilling and completion records.

Although extended reach (ERD) and horizontal drilling has been successfully applied in many other field developments (Figure 1), it has been most effectively applied in two offshore southern California oilfields (Pt. Pedernales and Dos Cuadras) and in the redevelopment of a Dutch North Sea project (Helder). The offshore California applications have resulted in the development and subsequent patenting of new ERD/horizontal completion tools and technology that were key to the successful completion of these wells, and in the process, several World and North American ERD/horizontal drilling and completion records were established.

Moreover, the developed technology, and drilling and completion techniques have been or are planned to be utilized by other oil companies worldwide.

The following paper overviews the application of ERD and horizontal drilling in the three aforementioned offshore oil fields, including a brief field overview, application of the technology, engineering considerations, and completion tool description, etc. The paper also describes other techniques and skills that have been important in completing these projects.
Mechanism of Oil Recovery by Gas Diffusion in Fractured Reservoir in Presence of Water
Authors: Le Romancer J-F. X. , Defives D. F. , Fernandes Gerard
Published: December 2007

The purpose of this study is to experimentally examine the effect of gas diffusion in the matrix blocks of light oil fractured reservoir subjected to gas injection. Experiments are performed in 1-D conditions on a chalk core saturated with a methane-pentane mixture in presence of different water saturation levels and with two diffusing gases: nitrogen and methane.

It has been found out that:

– Similarly to previous experiments performed without interstitial water, saturation profiles reveal a strong capillary end effect for nitrogen injection with an accumulation of oil near the fracture. – The impact of water saturation on recovery depends strongly on the nature of the diffusing gas. In case of methane injection along the fracture, the faster the oil withdrawal at the fracture, the higher the water saturation level. In case of a nitrogen injection, the methane production is proportional to the hydrocarbon mass initially in place whereas pentane production remains unchanged.

In addition to that, in case of nitrogen injection, the variations of the differential pressure are pointing out discontinuity in the gas phase occuring between the fracture and the bulk of the porous medium. This gas build up is attributed to local change in the mixture composition induced by diffusion in the liquid.
Leadership, Rewards, and Recognition
Authors: Mungan Necmettin
Published: December 2007

The petroleum industry is facing continual and intense challenges to operate with fewer staff in an increasingly more complex and competitive business world. each company wants to be better than the "competition" which requires a number of things, ■highly trained staff■applying the best technology■team work■a suitable system of rewards and recognition

Senior Management must institute rewards and recognition for individuals as well as teams which produce outstanding results and contribute to profits. Properly applied rewards and recognition promote team leadership, motivates all team members and help companies hang on to real achievers.
Reverse Osmosis System Reduces Demineralized Water Costs
Authors: Roberts J. A.
Published: December 2007

In the past, ion exchange has been the widely used method for demineralizing water. During the past decade, however, the use of Reverse Osmosis (RO) water treatment technology has become much more prevalent. Several reasons for the success of RO include consistently high water quality, low cost, and ease of operation.

This paper describes a case in which replacing an ion exchange system with a RO system reduced water demineralization costs at a cogeneration facility (cogen) by 65%. The operation of both the ion exchange and the RO system are explained. In addition, a cost comparison of the two systems reveals the tremendous potential for savings associated with RO.
Multiphase Production Metering in Field Applications
Authors: Blacker H. F. , Rutter M. G.
Published: December 2007

This paper reports the results from an extensive field testing program of flow meters and water cut probes at Midway Sunset (MWSS) Field. During a six month period, a continuous data collection system was used in conjunction with a line sampling program to determine the best equipment for multiphase metering applications on these Thermal EOR leases. This paper discusses data collection and analysis from the field test, providing insights into the relative merit and operational limitations of some of the different flow meters and water cut probes available to the industry.
Phase Behavior of Reservoir Fluids in the Stevens Zone at Elk Hills Oil Field, California
Authors: Ezekwe Nnaemeka , Querin M. E. , Humphrey Michael
Published: December 2007

Extensive PVT data were collected from Elk Hills Stevens reservoirs over a period of 34 years. PVT reports exist for thirty-eight bottom hole samples and five recombined samples. The reports are available upon request to other companies operating the Stevens or similar reservoirs.

PVT correlations are provided for estimation of routine properties such as: bubble-point pressures, oil formation volume factors, solution gas-oil ratios, saturated oil viscosities, undersaturated isothermal oil compressibility factors etc.

Availability of excellent PVT data has been very useful in the development and execution of management strategies for the reservoirs.
The Combined Effects of Curvature, Tension, and Pressure on the Ovality and Collapse of Oilfield Tubulars
Authors: Akgun Ferda , Mitchell B. J.
Published: December 2007

Oilfield tubulars can not preserve their original circular shape under the combined effects of hole curvature and tension. The deformed tube resists to a collapse pressure less than a circular tube. On the other hand, mud pressure across the tube flattens the tube. This paper explains the method of solutions and presents the numerical and graphical solutions to these two problems.
Production Optimization of a Mature Gas Field
Authors: Leong J. K. , Tenzer J. R.
Published: December 2007

This paper summarizes production optimization of a mature gas field, located in the Sacramento Valley near Stockton, California. A substantial increase in gas production was obtained at a very low cost.

It involves the various applications of reservoir and production engineering: Nodal analysis, recompletion, and acid stimulation. To keep the cost down and minimize formation damage, all the work was performed through-tubing without pulling the well.
New Packer Design Offers Completion Flexibility in Thermal Completions, ESP, Downhole Monitoring Systems, and Annular Safety Systems: Case Histories
Authors: White P. M. , Restarick Henry , Setterberg J. R.
Published: December 2007

The economic climate of the oil and gas industry has continued to decline over the last decade, increasing the need for operators to find newer operational strategies that will enhance efficiency, and subsequently, stimulate economic recovery. Production technology has responded to these needs by continually improving completion technology. This paper will present one of the new technological advances, a variable-bore packer, that supports current oil field needs by providing operators with a new concept in completion configuration flexibility.

Several case histories will be included in the paper and will outline applications using the new packer.

These case histories involve:

An electric submersible pump completion in which one bore was provided for production and one for electric cable penetration. Running dual production strings in a steam injection, enhanced-oil-recovery well. Use of packer as a single-bore production packer with three monitoring line ports for pressure and temperature surveys. Use of the packer as an annular safety valve packer in the North Sea.

The case history data will verify the operational simplicity, versatility, and reliability of the new packer and how its unique flexibility supports the current needs for greater operational efficiency.
Extended Reach, Horizontal, and Complex Design Wells: Challenges, Achievements and Cost-Benefits
Authors: Blikra Harald , Drevdal K. E. , Aarrestad T. V.
Published: December 2007

The paper describes Statoils experiences in drilling extended reach (ERD) wells, to primarily serve remote parts of widespread reservoirs and experiences in drilling horizontal and complicated wells, specially designed for optimal drainage of complex reservoirs. Several world records in exteded reach drilling, conducted from the Statfjord "C" platform are summarized. The latest ERD well drilled has a horizontal reach of 7290 m.

Included are also the latest plans of implementing these technics in developing new fields.

A brief summary is given on the achievements within the industry regarding other special well types, such as dual lateral, snaky, multiple arm, etc.

Furthermore the paper describes technical challenges of drilling complex wells and how planning is done to cope with these challenges.

Some limitations to the drilling are highlighted and solutions to drilling problems related to torque, drag, buckling, hole cleaning and surveying are given.

Cost-Benefit considerations regarding ERD, horizontal and complex wells are discussed.

Reducing number of platforms and/or leave out subsea templates due to ERD wells are considerable cost reducing factors.

Reducing the total number of wells from a platform due to horizontal and/or complex well profiles is another major cost reducing factor.
Reservoir Simulation Using a General Processor and an Array Processor in Parallel
Authors: Johnson Olin G.
Published: December 2007

Johnson, Olin G., IBM Scientific Center

In this paper, we describe an array or vector processor that, with only one basic arithmetic operation, can be used in parallel with a central processor for numerical reservoir simulation. In doing so, we demonstrate a partitioning of the problem to balance the partitioning of the problem to balance the computational load between the processors under the constraints imposed by the instruction sets and the relative speeds. We also discuss certain mathematical aspects of the partitioning and the iterative algorithms. Finally, we present results from numerical experiments using present results from numerical experiments using the IBM 2938 Array Processor with an IBM 360/85, 75, 65 or 44.

Index Terms for IBM Subject Index

Array Processing Mathematics Reservoir Modeling Numerical Analysis ADI Computer Applications SOR IBM 2938

Introduction

Much has been written recently in the area of parallel computation. Some problems have been attacked by using several identical general purpose processing units sharing a common purpose processing units sharing a common memory bank. Other problems have motivated the design of some highly parallel, special purpose arithmetic units arranged in two-dimensional arrays, each with its own memory and each with the ability to communicate with some of its neighboring units.

In this paper, we consider a very elementary type of parallel computation that is a combination of these two types. The idea is to augment a general purpose computer with an auxiliary arithmetic unit of special type. The computational objective is to place a large part of the computational load arising out of problems such as numerical reservoir simulation in problems such as numerical reservoir simulation in the special unit. This objective dictates that the unit be floating point and operate at high speed on vectors and band matrices. The economic objectives are to create a system that is much less expensive than two general purpose central processing units and that is several times as fast as a stand-alone central processor. processor. In particular, we show that if the auxiliary arithmetic unit, which we will henceforth call the array processor, contains only one basic vector function, then we can construct a parallel algorithm for reservoir simulation. parallel algorithm for reservoir simulation. Further, we have implemented this algorithm on an IBM 360/44, 65, 75, 85 with an IBM 2938 array processor and we present numerical results from processor and we present numerical results from these programs. In Section 2, we give a functional description of the array processor. In Section 3, we identify the basic computation kernels in a standard reservoir model.