bluuebunny/crossref_metadata_2025 huggingface dataset:
Field Evaluation of an Impermeable Cement System for Controlling Gas Migration
Authors: Cheung P. R. , Myrick B. D.
Published: December 2007

The petroleum industry has recognized the problem of gas flow after cementing for more than two decades. Several laboratory investigations and field studies have been conducted in an attempt to solve the gas migration problem. However, most of the previous field practices designed to control the gas migration problem have been either unsuccessful or only partially successful.

A study of the cause and a laboratory-developed solution for controlling the gas migration problem were presented in SPE 11207. The present paper summarizes the field results obtained during an eighteen-month period using an "impermeable cement" system to control the gas migration problem. Results of 84 cement jobs performed in Texas, Oklahoma, New Mexico and Louisiana are summarized, and unique field cases are discussed in detail. All four major types of cementing jobs have been performed using the "impermeable cement" system and an overall success ratio of over 90% was obtained.
Resin-Coated Sand Slurry Pack Gas Deliverabilities: Field and Laboratory Results
Authors: Nelson Chris , Wilson Bill , Stadleman Jeff
Published: December 2007

Although through-tubing resin-coated sand slurry packs (RCSSP's) are significantly less expensive than conventional gravel packs, they have not been widely used as a sand control completion technique. This low usage is mainly due to two inherent problems. The first is the high risk of localized pack failure in the perforation tunnels when the RCSSP casing plug is milled out. The second problem is the difficulty associated with predicting flow rates (and therefore economics) of RCSSP completed wells, especially if the casing plug is not milled out.

This paper presents a modified velocity coefficient correlation for gas turbulence, an innovative RCSSP completion configuration with an associated simulation technique, and supporting field results that demonstrate an expanded application for RCSSP's in the area of gas well through-tubing plugbacks where, until recently, their general application was thought to be uneconomical.
Single-Well Evaluation Program for Micellar/Polymer Recovery, Main and 99 West Pools, West Coyote Field, California
Authors: Holland K. M. , Porter L. T.
Published: December 2007

The Main and 99 West Pools of the West Coyote Field were selected as promising candidates for a micellar-polymer recovery project. Waterfloods initiated in 1961 are nearing their economic limit, with a current water-oil ratio of 45. Well MC 374 was drilled in a watered-out portion of the Main and 99 West reservoirs to accomplish an evaluation program with the following objectives: Provide data for an improved geological model.Estimate current oil in place.Determine the effectiveness of micellar-polymer chemicals in displacing residual oil.

MC 374 was extensively cored and logged to provide the necessary geological and reservoir data. A multi-well interference test was conducted to confirm reservoir continuity near the test well. Displacement tests were run in two intervals with micellar-polymer chemicals. Oil saturations in the near-wellbore area were measured before and after the displacement tests using log-inject-log and single-well-tracer techniques. An extended polymer injectivity test was conducted in one of the intervals.

This paper summarizes the various phases of the overall program, from chemical selection to field operations. Primary emphasis is on the various techniques used for measuring fluid saturations and the result of those measurements.
The Single Steel Drilling Caisson: A Novel Approach to Bottom-Founded Structures in Arctic Waters
Authors: Fitzpatrick John
Published: December 2007

In 1982, a mobile, bottom founded steel caisson drilling system, was conceived, constructed and installed on an underwater sand berm in 31 m of water, in the active shear zone of the Canadian Beaufort Sea. Discussed below are the principal design criteria, the ice/structure/foundation interaction, the construction and installation, and the post set down stress analysis of the steel caisson.
Comprehensive Geological and Reservoir Engineering Evaluation of the Lower San Andres Dolomite Reservoir, Mallet Lease, Slaughter Field, Hockley County, Texas
Authors: Behm E. J. , Ebanks W. J.
Published: December 2007

The Mallet Lease, Hockley County, western Texas, produces oil from the Permian San Andres Dolomite as part of the larger Slaughter Field. The Mallet Lease is being considered for infill drilling and for tertiary recovery. This paper discusses the engineering and geologic basis of the reservoir description that is used in history matching 40 years of primary and secondary performance. Emphasis is given to integration of reservoir description with necessary fluid flow properties needed to match performance and also the use of long term data to insure proper reservoir representation.

There are no discontinuous, isolated portions of the reservoir that would be tapped by infill wells. Most of the remaining oil is located in the tighter portions of the producing intervals which bears on prospects for infill drilling and tertiary oil recovery.
Bonus Bidding and Bottom Lines: Federal Offshore Oil and Gas
Authors: Lohrenz John , Dougherty E. L.
Published: December 2007

Much can be observed in the statistics of bonus bids. For one thing, more information about a lease may not mean bidders agree more with their bids. However, whether any or all bidders are achieving satisfactory results at their bottom lines cannot be observed from bid statistics. Indeed, it does appear that bidders' results are not satisfactory. Furthermore, an aggressive bidder who "wins" at bidding time appears, in this study, less profitable than a conservative bodder.
Binary Surfactant Mixtures for Minimizing Alcohol Cosolvent Requirements
Authors: Lelanne-Cassou C. , Carmona I. , Fortney L. , Samii A. , Schechter R. S. , Wade W. H. , Weerasooriya V. , Yiv S.
Published: December 2007

The role of alcohols in microemulsion formation is two-fold. They are used to bring the oil/water/surfactant system to its optimum formulation and they destroy highly extended structures, generating instead microemulsion. Given the freedom of choice among surfactants and their mixtures, the former role of the alcohol can easily be obviated. However, the latter requirement is more fundamental and not so easily removed. This study provides guidance in the purposeful construction of mixtures of synthetic surfactants which can minimize or eliminate alcohol requirements, depending on temperature and salinity. The approach was to mix straight tailed (high solubilization) species with mid-chain branched (low cosolvent requirement) species in a spectrum of mole ratios and reduce the alcohol concentration to the point that phase transitions destroyed the microemulsion. A number of systems were identified with acceptably large solubilization parameters and no residual cosolvent requirements.
A Study for Development of a Plan of Depletion in a Rich Gas Condensate Reservoir: Anschutz Ranch East Unit, Summit County, Utah, Uinta County, Wyoming
Authors: Kleinsteiber S. W. , Wendschlag D. D. , Calvin J. W.
Published: December 2007

The Anschutz Ranch East field is the largest hydrocarbon accumulation discovered to date in the Western Overthrust Belt. Analyses of reservoir fluid samples from the discovery well indicated that the fluid is a rich gas condensate with liquid dropout under reservoir conditions as high as 40 percent of the hydrocarbon pore volume. The proximity of the fluid dew point pressure to the original reservoir pressure dictated that a plan-of-depletion be established very early in the life of the field to avoid reservoir damage and the potential loss of significant liquid reserves. This requirement was further amplified by the fact that some of the depletion alternatives involved major front-end monetary commitments and long lead times for implementation.

Using preliminary reservoir data together with compositional simulators, various depletion alternatives ranging from primary depletion to full pressure maintenance were evaluated. Variables examined in the study included such factors as type of injection fluid and injection-production well configuration. Full pressure maintenance using nitrogen preceded by a hydrocarbon-nitrogen gas buffer in an inverted nine-spot pattern was selected as the most attractive depletion method. This plan was approved by the working interest owners and state regulatory agencies and is currently being implemented.
A Reservoir Engineering Study of an Over-Pressured, Partial Water-Drive Gas Field in Southern Louisiana
Authors: Sharpe G. F. , Van Kirk C. W.
Published: December 2007

The purpose of this paper is not just to present a case history, but also to provide guidelines for performing a reservoir study, and in particular, a material balance analysis. The study involved manipulating a complex material balance equation into forms which isolated certain input parameters. The forms were used graphically not only to estimate the OGIP, but also to verify those parameters used in the analysis. Production decline curves were used in conjunction with the material balance equation to predict future reservoir performance. Theoretical recovery calculations justified the future predictions.
Steam Generation Using Multi-Solids Fluid Bed Combustion Technology For Heavy Oils And Tar Sands Recovery
Authors: Jones Oscar , Britton Michael W.
Published: December 2007

Conoco is successfully operating a prototype 50 MMBTU/hr., solid fuel-fired, Multi-Solids Fluid Bed Combustor (MS-FBC) to generate 80% quality 2450 psig steam for tar sands recovery from the San Miguel-4 formation in Maverick County in South Texas. The facility is designed to bum high ash coal or high sulfur petroleum coke with environmentally acceptable emission levels of SO2, NOx CO and particulates. More than 8,000 hours of on-line operation have been logged since startup of the fluid bed combustor in January 1982.

This paper describes the selection process and criteria used by Conoco in selecting this technology, the key process design considerations and comparative economics with conventional oilfield steam generators. It also discusses the overall system performance and plant modifications which have contributed to improvements in the operability and reliability of the fluid bed combustor steam generator.
Analysis of Five Field Tests of Steamdrive Additives
Authors: Doscher T. M. , Kuuskraa V. A. , Hammershaimb E. C.
Published: December 2007

CLD Technology, Inc. is developing additives to steam which are intended to increase both the economics and the amount of oil recovered in steam injection operations. CLD's initial project was started under a contract with the U.S. Department of Energy in October 1979 for the express purpose of developing and demonstrating the efficiency of "foam blocks" to increase the efficiency of the steam drive.

After extensive laboratory research and development and five field tests, it can now be concluded that the efficiency of the steam drive can indeed be increased in particular reservoirs by the use of the proper additives.

Continued research has demonstrated that the particular additives being developed do alter injection profiles and increase the ability of steam to transport the heated crude oil. Employing a hypothesis concerning the mechanism by which oil is displaced by steam, superior additives have now been developed based on the results of laboratory screening tests.
Field Application of an Additive Containing Sodium Metasilicate During Steam Stimulation
Authors: Mbaba P. E. , Caballero E. P.
Published: December 2007

This paper describes the successful application of an additive consisting mainly of sodium metasilicate in a steam soak operation. Numerous wells tested with a small concentration of the additive responded favorably. Laboratory testing of the additive has established that the alkaline nature of the additive is most effective under prolonged exposure to acidic crude at high temperatures.
Proppant Scheduling and Calculation of Fluid Lost During Fracturing
Authors: Crawford H. R.
Published: December 2007

When a well is to be fractured, it is helpful to have a quick accurate method to: determine the amount of frac fluid needed without wasteful overdesign, and toestablish an efficient proppant schedule which simultanteously provides high fracture conductivity, long propped lengths and low odds of a screenout.

An approach to this type of frac design is presented which uses the following equation. (1)A=V/(W+3CT0.5),    sq  ft
Compressed Air Energy Storage (CAES) in an Aquifer—A Case History
Authors: Istvan J. A. , Crow C. V. , Pereira J. C. , Bakhtiari Hushang
Published: December 2007

The CAES aquifer experiment is a research project which draws its basic knowledge from natural gas storage in aquifers. It does however pose problems of a typical nature, namely the properties of the storage product which has a higher viscosity than natural gas, the need to cycle daily rather than seasonally and the higher temperature requirements. This paper summarizes the test activities that are being conducted at the Pittsfield Aquifer Test Site, concerning the field evaluation of a typical aquifer for storing and cycling compressed air under conditions approaching those existing in a full scale CAES operation.
1982: A Precipitous Decline, The Service Company, Bidding and Integrity
Authors: Ely J. W.
Published: December 2007

From 1979 to 1982, the oil industry experienced a continual rise in the rig count. This ever expanding number of rigs caused the service company industry to undergo rapid expansion both from the standpoint of people and equipment. It was obvious that many of the companies looked at an ever increasing, upward spiral and planned expansion and requirements on that continued growth. The decline in rig count, which actually started in late 1981, was even more drastic than the upward spiral. Many service companies and suppliers for those service companies who had become highly leveraged found themselves in a very precarious position. In order to capture an ever declining market, many service companies resorted to extreme price cutting on available jobs. An examination of the profits of five representative companies during the good years is evaluated and compared to the profitability of companies during 1982 and early 1983. The response of both the service companies and the oil companies in a survival mode are evaluated. The keynote of the paper will be directed toward the free enterprise system, profit motivation, and ultimately, the survival of the oil service industry as we now know it.
Fracturing Operations in a Dry Geothermal Reservoir
Authors: Rowley J. C. , Pettitt R. A. , Hendron R. H. , Sinclair A. R. , Nicholson R. W.
Published: December 2007

Fracturing and completing deep wells in hot, non-porous crystalline basement rock challenges conventional equipment use, procedures, and techniques common in oil and gas and normal geothermal completions. Fracturing operations at the Fenton Hill, New Mexico, Hot Dry Rock (HDR) Geothermal Test Site initiated unique developments necessary to solve problems caused by an extremely harsh downhole environment.

Two deep wells were drilled to approximately 15,000 ft (4.6 km); formation temperatures are in excess of 600°F (315°C). The wells were drilled during 1979-1981, inclined at 35 degrees, one above the other, and directionally drilled in an azimuthal direction orthogonal to the least principal in-situ crustal stress field. The pair of wells form the injection and production wells of an energy extraction system which will be unique in reservoir development.

The test site is located near the flank of a young silicic composite volcano, the Valles Caldera, in the Jemez Mountains of northern New Mexico. The deeper well was planned as the cold water injection hole; as such, it may be cooled from the static, conduction geothermal gradient to as low as 80°F (25°C). The upper, production well will be heated to over 500°F (260°C) along its entire length. The well pair has been designed to be a closed loop, heat-extraction system formed with hydraulic fracture connections between the 1200 ft (370 m) vertically-spaced wells. These production conditions, and the in-situ formation temperatures, strongly constrain all completion hardware, cementing formulations and procedures, and fracturing operations.

Hydraulic fracturing experiments to connect the two wells have used openhole packers, hydraulic jet notching of the borehole wall, cemented-in isolation liners and casing packers. Problems were encountered with hole drag, high fracture gradients, H2S in vent back fluids, stress corrosion cracking of tubulars, and the complex nature of three-dimensional fracture growth that requires very large volumes of injected water. Two fractured zones have been formed by hydraulic fracturing and defined by close-in, borehole deployed, microseismic detectors. Initial operations were focused in the injection wellbore near total depth, where water injection treatments totalling 51,000 bbls (8,100 m3) were accomplished by pumping through a cemented-in 4-1/2-in. liner/PBR assembly. Retrievable casing packers were used to inject 26,000 bbls (4,100 m3) in the upper section of the open hole. Surface injection pressures (ISIP) varied from 4,000 to 5,900 psi (27 to 41 MPa) and the fracture gradient ranged from 0.7 to 0.96 psi/ft.
Successful High-Angle Gravel Packing Techniques
Authors: Nini C. J. , Owen G. W.
Published: December 2007

Gravel packing can be successfully performed on high-angle wells (70°-80°) when special consideration is given to the completion design and details of field procedures and practices. Through analysis and modification of current techniques and research done on full scale models, Chevron experimented with and developed several techniques to successfully gravel pack high-angle wells .

The high-angle gravel packs were performed utilizing the following criteria: solids free completion fluids, low-side perforating, modified screens, combination tools (circulating pack), maximum tailpipe (washpipe)-liner ratios, medium viscosity carrier fluids, maximum pumping rates, and special attention to quality control.

Sand-out pressures, subsequent pack tests, quantity of gravel placed (percent packed volume) and extended flow tests of up to 20 MMCFD have proven the success of the design and procedures implemented.
Hydraulic Fracture Orientation Using Passive Borehole Seismics
Authors: Dobecki T. L.
Published: December 2007

Passive borehole seismometry enables mapping the orientation of induced hydraulic fracture planes by using a triaxial seismometer clamped in the treatment well to map acoustic emissions from the fracture. Presently, the method utilizes only those seismic events attributable to shear failure along the fracture plane which exhibit both compressiona1 and shear wave phases. The fracture azimuth is seen to parallel the polarization of the compress iona1 wave phase. Whereas other geophysical techniques used to determine fracture orientation are principally surface-deployed measurements and, therefore, lose their effectiveness as the fracture depth exceeds 1500-2000 meters, the borehole seismic has worked effectively at 3300 meters in past applications. The method, principally, gives only fracture azimuth as is demonstrated by two examples of field test data.
Prediction of Conditions Necessary for Multiple-Contact Miscibility
Authors: Cohen G. S. , Shirer J. A.
Published: December 2007

This paper describes a method that predicts the minimum amount of enrichment of a hydrocarbon gas with intermediate weight hydrocarbons necessary to achieve a miscible fluid displacement in the reservoir. The method is based on the work of Benham, et.al1 and is an application of their description of the multiple-contact displacement process. The technique requires that compositional analyses are available for the hydrocarbon gas, intermediate weight hydrocarbons, and the reservoir fluid. In addition, a phase behavior simulator must be available to generate the foundation of the method, a pseudo-ternary phase diagram. The method has been used with two light crudes and two intermediate weight hydrocarbon mixtures, and has compared very favorably with laboratory slim tube tests.
Efficiency of a Single-Stage Cuttings Washer With a Mineral Oil Invert Emulsion and Its Environmental Significance
Authors: Jones Maurice , Burgbacher J. A. , Churan Marc , Hulse Michael
Published: December 2007

Questions and concerns about the use of mineral oils to replace diesel in invert emulsion drilling fluids for offshore oil and gas wells have centered on the treatment and disposal of oil wet cuttings. This study, using a modified 20 ml retort procedure, measured the percent retention (w/w) of mineral oil based mud on cuttings from the shale shaker and a single-stage cuttings washer at one offshore Texas well. The modified retort procedure was demonstrated to be a highly repeatable procedure. Retort results were then correlated to more sophisticated laboratory techniques (gravimetric, gas chromatographic, and IR spectrophotometric procedures) with good agreement to two of the three methods. Solid phase bioassays with three marine invertebrates (clam, worm, and shrimp) suggested that seawater washed cuttings were the most environmentally acceptable method. Further considerations suggest that the use of mineral oil-based muds may be enhanced relative to diesel oil-based muds if regulatory relief is achieved.
A Pressure Transient Method for Front Tracking
Authors: Benson S. M. , Bodvarrsson Gudmunder
Published: December 2007

A pressure transient technique for tracking the advance of cold-water fronts during water flooding and geothermal injection operations has been developed. The technique is based on the concept that the steady state pressure buildup in the reservoir region inside the front can be calculated by a fluid skin factor. By analyzing successive pressure falloff tests, the advance of the front in> the reservoir can be monitored. The validity of the method is demonstrated by application to three numerically simulated data sets, a nonisothermal step-rate injection test, a series of pressure falloffs in a multilayered reservoir, and a series of pressure falloff tests in a water flooded oil reservoir.
The Advanced Research Projects Agency
Authors: Frosch Robert A.
Published: December 2007

Publication Rights Reserved

This paper was 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. Permission to copy is restricted to an abstract of not more than 30 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 requested 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 discussions may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

The Advanced Research Projects Agency, generally known as ARPA, is a line agency responsible to the DDR and E in the OSD. When I use the term line agency, I mean simply that we are responsible for planning and accomplishing work rather than giving advice on what to do and how to do it. ARPA is responsible for sponsorship and management of R and D work aimed at the improvement of U. S. defense capabilities. The particular projects and fields that we work on are assigned to us by DDR and E. It is frequently the case that we see the need for work in a particular area, do the basic planning, and go to DDR and E with the request that the work be assigned to us. Several of our present projects arose in just such a manner. ARPA does not generally compete with the research and development of efforts of the individual services. Rather we specialize in work that is either not obviously the province of any one service, or may be the province of several services. We also provide a fast action capability directly responsive to the Secretary of Defense and the DDR and E for the accomplishment of Department of Defense research and development projects. In addition to the regular ARPA-assigned work, we also sponsor and monitor for the ODDR and E specific technical studies and analyses that he or his staff may desire to have done.

The present annual budget of ARPA is about 275 million dollars. We have 125 people stationed in the Pentagon. Of these about 75 are professionals including 25 military officers. We consider the military officers professional not only because of their military competence but because they are generally scientists or engineers with advanced training in technological disciplines. In addition to the Washington group there are about 55 people stationed overseas in field units connected with Project Agile (which I will describe shortly).

At the present time, we have 7 technical offices. Of these three are concerned with projects having specific military or national goals, and four are concerned with research and development in general technological areas.
Numerical Simulation of Aquifers Using Transient Grid Block Properties
Authors: Syed-Kechik M. B. , Hutchinson H. L.
Published: December 2007

An empirical, time-dependent correction of the block transmissibility for an aquifer block in a numerical reservoir model was derived. This correction allows the use of a single, large block to more accurately represent the aquifer behavior over long simulated time periods than does a single block without the correction. This allows savings in computing time over having to use multiple blocks for the aquifer while allowing comparably accurate results to a multiple block representation. Results are shown for a one-dimensional representation of a black-oil reservoir.
Mechanical Properties of Geopressured Core and Their Influence on Reservoir Performance: T-F&S/DOE Gladys McCall No. 1 Well
Authors: Kelkar S. M. , Cooley C. H. , Schatz J. F.
Published: December 2007

Reservoir deformations associated with large pore pressure drawdowns can play a significant role in the production performance of deep oil and brine reservoirs. In order to evaluate these effects, laboratory measurements were performed at simulated in-situ conditions on core from geopressured production intervals from the T-F&S/DOE Gladys McCall No. 1 Well, Cameron Parish, Louisiana. The test conditions ranged around 15,000 psi (103 MPa) confining pressure, 4000 psi (28 MPa) vertical deviatoric stress, and 13,000 psi (90 MPa) pore pressure at temperatures of 300°F (149°C). Reservoir drawdown was simulated by reducing the pore pressure at constant lateral strain and overburden stress. Elastic moduli, failure strengths and creep rates were determined from the tests. A number of permeability measurements were also carried out.

The effect of reservoir drawdown on the production potential was assessed by combining these measurements with a simple one-dimensional liquid phase reservoir model. It was found that creep rates considered very low on the laboratory scale may have a significant effect on the production. Recoverable reserves were found to increase by as much as 25-50% due to creep compaction.
Application Of Open Hole Acoustic Amplitude Measurements
Authors: Anderson Warren L. , Walker Terry
Published: December 2007

Publication Rights Reserved

This paper is to be presented at the 36th Annual Fall Meeting of the Society of Petroleum Engineers of AIME in Dallas October 8–11, 1961, and is considered the property of the Society of Petroleum Engineers. Permission to publish is hereby restricted 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 JOURNAL OF PETROLEUM TECHNOLOGY or the Executive Secretary. Such abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in 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 considered for publication in one of the two SPE magazines with the paper.

In acoustic velocity logging the phenomena of cycle skipping has been used to indicate the presence of fractures, etc. Since the cycle skips of interest are the result of attenuation of the acoustic signal, a measurement of formation amplitude is a more positive means for this purpose. In the field of acoustic bond logging the amplitude of the formation signal depends to a great extent upon the quality of bonding of cement to pipe and formation. By comparing the open hole acoustic amplitude to that in cased hole, the over-all effectiveness of the cement job may be more clearly distinguished.

Test well data is included to show the degree of attenuation of the acoustic signal at solid, liquid interfaces as would be present in fractured formations. Field examples of this and other applications of amplitude measurement are included to illustrate the effectiveness of the application.

Introduction

In the past there has been some use of acoustic velocity logs for the location of natural formation fractures and shallow gas sands by the presence of cycle skips on the log. This cycle skipping is the result of the amplitude of the acoustic signal being reduced to the extent that the trigger skips over to a later pulse of the signal. In fractured formations this reduction in signal amplitude is caused by the large reflection of energy and lower transmission at any interface where there is a large density change such as from limestone to water or oil, thus there is a lower signal amplitude at the receiver than if the fractures were not present.
The Use of Flexible Gridding for Improved Reservoir Modeling
Authors: Quandalle Philippe , Besset Philippe
Published: December 2007

This paper describes some model improvements developed to allow new possibilities in reservoirs representation with simulators using a finite difference scheme. It includes: possibility of flow between any grid block and from one to many blocks;a multiple time step calculation which allows to solve flow equations with several time step lengths for different group of grid blocks.

These facilities provide a flexible and performant way of handling irregular and complex grid patterns with different nested levels of refinements. They are particularly useful to accurately simulate: –unconfined pilots or areas with smaller wells spacing;–faulted reservoirs;–vanishing or discordant geological layers;–reservoirs connected to a general aquifer.

The new approach has been tested on a black oil simulator, implicit in pressure, implicit in saturation.

The solutions used for some important aspects of model design are outlined. These are the Input/Output data organisation, the inner model grid pattern representation, the matrix solver, the multiple time steps selector and the associated equation solver.

Two examples illustrate the use of the modified black oil simulator, and results are presented.

The first example concerns the simulation of a repeated five spot injection. This test is made to check the local mesh refinements efficiency.

The second example is a full field reservoir study for which using the modified model is suitable. The performance of a produced oil reservoir connected to an aquifer is simulated.

In both cases, results obtained with a composite grid and the modified model are compared to those obtained with a coarse grid and then a fine grid used on a conventional model. The following points are outlined: –the use of local grid refinements give results very closed to those obtained with the fine gridded conventional model;–on the computers used, the running time of the modified model simulations is much lower than the time needed for the conventional model.

Moreover, it is shown that the modified model results remain unchanged when the multiple time step selector is used. A different time step length is then automatically calculated for the oil reservoir and the aquifer, thus allowing a noticeable extra gain of processing running time.
A New Formulation for Numerical Simulation of Compaction, Sensitivity Studies for Steam Injection
Authors: Espinoza C. E.
Published: December 2007

A thermal simulator was modified in order to study the effect of different formulations of the compac tion phenomenon in modelling steam injection processes. The modified model can simulate total or partial irreversibility of this phenomenon, as well as the reversible formulation commonly used. Options to recalculate block permeabilities, transmissibilities, and thermal conductivities according to changes in porosity and thickness due to compaction are included.

Results from a series of simulations using data of hypothetical reservoirs are presented; these show a strong dependence of the quantities injected and produced, with the chosen formulation for compaction. It is found that the results are more sensitive to changes in the pore volume, than to changes in permeability and transmissibility.

This improved representation of the compaction phenomenon in the simulator, proved to be of great help to understand injection and production mechanisms in steam injection processes. It also widens the possibilities of using reservoir simulators for history match purposes, and also enables the user to take more into account the compressibility data obtained from laboratory experiments.
A Seven-Point Finite Difference Method for Improved Grid Orientation Performance in Pattern Steamfloods
Authors: Pruess Karsten , Bodvarsson G. S.
Published: December 2007

This paper presents a novel seven-point finite difference approximation for simulations of adverse mobility ratio displacements. The method is based on partitioning of a two-dimensional flow domain into regular or nearly regular hexagons. The accuracy of the method for pattern steam-floods of heavy oil reservoirs is compared to five-and nine-point approximations. For five-spot floods, the accuracy of the seven-point method is good and comparable to that of the nine-point scheme. For seven-spot floods, the seven-point method provides good numerical accuracy at substantially less computational work than five-or nine-point methods. For nine-spot floods, only the nine-point method is found to give accurate results.
Numerical Solution of the Buckley-Leverett Equations
Authors: Sethian J. A. , Chorin A. J. , Concus Paul
Published: December 2007

A modified random choice method is described for solving simultaneously the Buckley-Leverett, incompressibility, and Darcy's Law equations for immiscible displacement in a porous medium. The main idea of the numerical method is to modify the one-dimensional Riemann solvers in the split random choice method so that the multidimensional flow is represented correctly. Other features include flux conserving differencing of pressure and velocity and an accurate description of sources and sinks. Numerical results for a two-dimensional five-spot waterflood indicate that the advancing front is kept sharp by the method, that the time of breakthrough is accurate, and that grid orientation effects are unimportant.
Practical Considerations for Incomplete Factorization Methods in Reservoir Simulation
Authors: Behie Alda , Forsyth P. A.
Published: December 2007

Various incomplete factorization (ILU) methods coupled with ORTHOMIN acceleration are discussed. These include natural, D2 and D4 orderings with several degrees of factorization, the modified factorization (MILD) and the COMBINATIVE method. These techniques can also be used with the bordered systems resulting from fully-coupled, fully-implicit multi-block wells. Test results are reported for fully implicit black oil and fully implicit thermal simulations. Some results are also reported for vector and scalar modes on the CRAY.
Incorporation of Mixed Finite Element Methods in Compositional Simulation for Reduction of Numerical Dispersion
Authors: Ewing R. E. , Heinemann R. F.
Published: December 2007

Previous studies have shown that standard finite difference techniques cause numerical dispersion and grid orientation problems when used to simulate enhanced recovery processes with adverse mobility ratios. In compositional simulation, numerical dispersion can diffuse sharp fluid interfaces yielding erroneous predictions of fluid compositions and corresponding errors in the velocities of the miscible frontal advance. Numerical dispersion can also effect the computed locations of the boundaries of the regions of single-phase and two-phase flow.

Inaccurate fluid velocities and suboptimal use of upstream weighting of transport terms combine to cause many aspects of the numerical dispersion and grid orientation problems. A mixed finite element method has been developed to obtain more accurate approximations to the fluid velocities. In this method the Darcy velocities are considered as primary variables together with the total fluid pressure.

Although finite element techniques are used to compute the more accurate fluid velocities, these velocities are then incorporated into a more standard finite difference method for the bulk of the simulation process. This paper presents the use of mixed methods in a two-dimensional finite difference compositional simulator to reduce problems caused by numerical dispersion. Comparisons are made with a standard finite difference simulator on problems involving immiscible displacement and multiple contact miscibility phenomena.
A Practical Numerical Simulator for Three-Dimensional Fracture Propagation in Heterogeneous Media
Authors: Barree R. D.
Published: December 2007

A numerical simulator capable of predicting fracture geometries during propagation in both height and length directions has been developed. The simulator is capable of handling random spatial variations in elastic properties, confining stress, pore pressure, and rock strength. Fracture fluid pressures, fracture widths, and net stresses are calculated at uniformly spaced points over the entire fracture face.

The solution of the problem combines a finite difference formulation for calculation of fluid flow within the crack with an integral equation for fracture width. The fracture width equation is based on the work of I. N. Sneddon, but eliminates some of the simplifying assumptions he introduced.

Results of simulation of laboratory fractures under various stress conditions are presented. The effects of varying rock properties and stresses on fracture containment are shown.

The general nature of the formulation, with its flexibility in handling any number of randomly arranged rock formations, is ideal for application of the simulator to the prediction of hydraulic fracture geometries under field conditions. Input and output of the model are easily comprehensible and convenient to the user.
Mathematical Modeling of 15-meter Subsea Wellheads
Authors: DaMota Augusto C.
Published: December 2007

A mathematical model has been developed for subsea wellheads to calculate bearing and hoop stresses. For hoop stress calculations a tentative critical cross section has been introduced which, although controversial, gives results which correlate remarkably well with field tests.

Wellheads designed according to the conventional geometry exhibit high stress levels both in collapse and/or bearing loading. Existing systems have been found to be good up to 5,000 psi WP (SOUR SERVICE). At higher pressures, it has been found that existing systems rely on friction, which is very limited when oil-based muds are used.

The model shows that stress levels do not depend on wellhead sizes but solely on the relative through bores of housings and hangers. This is contrary to the accepted practice of using small bore wellheads with conventional geametry to cope with high pressures.

Accordingly, a revised geometry has been recommended for the design of systems for higher working pressures.

Application of the results given by this model will minimise expensive failures and tedious full scale model tests.
Pumping Unit Geometry vs. Prime Mover Speed Variation as a Method of Torsional Reduction in a Beam and Sucker Rod Pumping System
Authors: Byrd J. P.
Published: December 2007

Theoretically, it is possible to effect a significant reduction in peak (in-balance) torque, with resulting cost savings, in a beam and sucker rod pumping system by two different methods. The first is the optimum selection of unit geometry; while the second employs a special, low inertia (or high slip) prime mover, permitting the unit's speed variation to more closely respond to the torsional load demand. Following is a discussion of a comparative study using the most advanced predictive technique, covering two field applications, which illuminates the relative effectiveness and economy of both methods on the torsional loading of beam pumping units, as well as the effect on other selected parameters.
Opportunities for Investment
Authors: Gaffney Peter D. , Moyes C. P. , Archer J. D.
Published: December 2007

The past ten years have seen major changes in the Asia Pacific petroleum position. Significant new offshore reserves have come onstream, as have major gas fields and LNG facilities. The region as a whole, while not totally insulated from the cycle affecting the worldwide petroleum business, nevertheless has retained a more comfortable position in the most recent recession, protected by the indigenous demand in the region, prior success ratios and the relatively attractive economics.

Significant discoveries of gas within the region have created a position of over-abundance as it remains difficult to develop indigenous gas utilization — something which must be a task over the next decade.

The prospects, opportunities and legislation in many countries are excellent, the question must be whether the industry will extend its efforts further and whether other competing regions get a greater share of exploration dollars in the next decade as many of the competing areas lie in hostile, expensive environments. We continue to believe that the signs remain set for continued growth in the region across a broad spread of the industry.
History and Geology of the Tinggi Field Offshore Peninsular Malaysia
Authors: Brami J. B.
Published: December 2007

The Tinggi field is the fifth field put on production by Esso Production Malaysia Inc (EPMI), off the East Coast of Peninsula Malaysia. It is the first proposed for development on the basis of only one exploration well. Currently it produces from four differ nt sandstone units namely the J-16, J-17, J-18/20 and K-20/30. The Tinggi field is located approximately 260 kilometres east of Kuala Trengganu Figure 1 in 73 metres of water. Of the twenty-seven wells presently planned for the field, twenty-five have been drilled to date and of these, only one well was sidetracked to an alternate location due to hole problems.
Full Wave Acoustic Logging: Some Examples
Authors: Minear John W , Ajam Sami O
Published: December 2007

More information about formation properties than is commonly utilized is available in the acoustic signal. The objective of full-wave acoustic logging is to use more of this information to determine formation properties.

Full-wave acoustic tools generally have transmitter-to-receiver spacings greater than about eight feet. This provides deeper penetration and facilitates signal analysis. Full-wave acoustic signals are briefly discussed.

Shear wave slowness, or Δts, is one of the most important new acoustic logging measurements. Used with ∆tp, ∆ts provides basic log quantities for lithology identification, gas zone identification, estimation of lithology and porosity with acoustic logs only, and improved formation elastic property estimation.
Is There a Satisfactory Classification for Southeast Asian Tertiary Basins
Authors: Hutchison Charles S.
Published: December 2007

From Jurassic through Early Miocene there was active rifting of the south China and north Australian continental margins. Magnetic anomalies of the marginal seas indicate that microcontinents were drifted as far as Borneo. Together with island arcs, these microcontinents formed the nuclei against which distal turbidites accumulated, with their source perhaps as far away as the Mekong Delta.

The post Oligocene convergence of Australia and the Philippines against Indonesia, effected by subduction of extinct marginal sea lithosphere, resulted in uplift of the ancient microcontinents and their turbidite drapes to form new provenance landmasses for shallow water sedimentation in adjacent basins.

Plate tectonic basin classification cannot be successful unless the important role of the microcontinents is recognised. Their presence in the Southeast Asian developing orogen hinders the formulation of an elegant classification.
Simplified Strength Analysis of Jack-Ups
Authors: Carlsen C. A. , Odland J.
Published: December 2007

New challenges are posed on structural analysis of jack-ups when moving to deeper water, more harsh environment and application high tensile steel. Dynamic behaviour becomes more prevailing and fatigue due to wave loads may become governing. Furthermore, supply boat sizes tend to increase and they work in more severe weather conditions, increasing the risk for collisions with the jack-up legs.

The present paper describes simplified ways to cope with the effects above.
Development of the thin Oil Zone Underlying the Snapper Gas Field
Authors: Seage N W , Lau J , Koh S T
Published: December 2007

This paper describes the successful development by Esso Australia Ltd (Operator) and BHP Petroleum Pty Ltd of the Snapper field which is located in the Gippsland Basin beneath the waters of Bass Strait off south-eastern Australia. Discussion is focussed on the development of a thin, "pancake" type oil column of 4 to 8 metres thickness which underlies the Snapper N-1 gas reservoir. The gas reservoir, which has a maximum gross thickness of 208 metres, comprises very high quality sandstones with interbedded shales, siltstones and coals.

A 27 conductor production platform has been installed in 55 metres of water with facilities for concurrent production of gas and oil. The timing of the development has permitted successful development of the thin oil column before major withdrawal of gas takes place.

Development of the oil zone was complicated by the presence of interbedded non-net sections which, combined with the varying thickness of the oil column provided significant well targeting challenges. Several high angle wells were required for oil production which presented drilling and logging problems. However, 16 of the 21 wells drilled succeeded in intersecting oil columns suitable for production. Performance of the oil wells has been very encouraging, but also variable with a wide range of producing GOR's, water cuts and wellhead pressures.

Thin oil columns of 2 to 15 metres overlying water and underlying a large gas cap are common within the Gippsland Basin and elsewhere. Snapper, the first development of one of these oil zones in the Gippsland Basin, has provided valuable and encouraging experience in performance of the wells, completions and surface equipment. This will assist economic assessment and facilities design for other with thin oil column development prospects.