bluuebunny/crossref_metadata_2025 huggingface dataset:
Malacca Strait Wrench Fault Controlled Lalang And Mengkapan Oil Fields
Authors: Crostella Angelo
Published: December 2007

The Lalang and Mengkapan oil fields are located within the Malacca Strait production sharing contract area, Indonesia, some one hundred and eighty kilometres west of Singapore.

Exploration of the 2.9 million acre area commenced in 1970, but the Lalang oil field was not discovered until 1980, following extensive seismic surveys and the drilling of eight dry holes. The discovery of the Mengkapan oil field followed in 1981.

In both fields the oil is reservoired within sands of the Sihapas Group of Early Miocene age. Geochemical data indicate that the shales interbedded within the Sihapas Group are the source rocks for the oil. Notwithstanding their young Late Tertiary age, these source rocks are mature for oil generation at a depth of burial of approximately 3,000 feet, due to the high regional geothermal gradient.

The trapping mechanism in both fields is controlled by the same regional north trending left lateral wrench fault. The Lalang accumulation occurs in an asymmetric anticlinal fold, bisected by the controlling wrench fault, and showing continuous growth since at least the Early Miocene. Both sections of the Lalang field have been tested; the oil/water contact is slightly shallower in the upthrown section. This appears to be a characteristic feature of the basin. The net oil pay penetrated by the Lalang — 2 discovery well on the western section of the structure is 153 feet and by the Lalang — 3 well on the eastern one is 316 feet. Cumulative flow rates obtained by drill stem testing were 7,092 bopd in the No. 2 well and 10353 bopd in the No. 3 well.

The Mengkapan accumulation is contained in an elongated upthrown half anticline to the east of and paralleling the controlling wrench fault. Four discrete oil pools totalling 234 ft. of net pay were penetrated in the Mengkapan No. 1 discovery well. Cumulative flow rate from 6 drill stem tests was 12,017 bopd.

The discovery of the Lalang and Mengkapan oil fields opens a challenging new horizon to oil explorers, as the prolific Tertiary Central Sumatra Basin has now been proved to extend offshore from the island of Sumatra into the Malacca Strait.
Maximization Of Footage Drilled Before Drill Steels Fail In Fatigue
Authors: Paul B. , Fu C.C.
Published: December 2007

Experiments indicate that the fatigue limit of various drill steels becomes vanishingly small in the presence of water and other corrosive liquids. Therefore one must generally expect fatigue failures of drill steels in a great many field operations. However, it is theoretically possible to so choose the hammer impact speed of a percussion drill in order to maximize the total length of hole drilled before failure occurs. In this paper the existence of an optimum speed is demonstrated and it is shown to be comparable to presently used piston speeds. The influence on drilling speed and hole length of a number of other pertinent design features, such as bit geometry, hammer geometry, and steel properties is also established.
An Iterative Matrix Solution Technique for Steamflood Simulation
Authors: Wallis John R. , Coats Keith H. , Vohra Ibrahim R.
Published: December 2007

Iterative techniques, such as line successive overrelaxation (LSOR), have generally proven to be ineffective in solving linear systems of equations arising in thermal reservoir simulators. This is partly due to the occurrence of negative effective compressibilities or transmissibilities which can occur when cold fluids move into blocks having steam saturations. This paper describes an effective iterative method for solving steamflood equations using partial elimination followed by block successive overrelaxation on the reduced matrix. This scheme has been implemented in a steamflood model allowing any number Nc of components. The model's implicit formulation requires the solution of a linear system of equations in which each grid block has Nc + 1 unknowns.

A cyclic steam stimulation process provides a severe test for the iterative technique. During the production portion of the cycle, cold fluids can flow into the steam zone causing the negative compressibility/transmissibility relationship mentioned above. The flow of cold fluids into a steam block is a physically real, dominant feature of both cyclic stimulation and steam-bank flooding. This paper presents data and model results for two such test problems, including comparisons of slice (planar) SOR, direct solution using D-4 ordering and the proposed method. These comparisons indicate that for three-dimensional problems involving a large number of blocks and/or components, this iterative approach can reduce storage by factors of two to four and CPU time by factors of three or more. In comparison with standard SOR techniques, the proposed method has proven to be significantly more reliable for steamflood problems.
A Three-Phase Model For Fractured Reservoirs Presenting Fluid Segregation
Authors: de Swaan Abraham
Published: December 2007

A model has been developed to describe the behavior of naturally fractured reservoirs with black oil in which high transmissibility in the fractures and low oil production rates allow the gravitational segregation of the gas, oil and water phases. The influxes of these fluids from the matrix rock to the fractures are described by functions dependent on the properties of the reservoir fluids and the matrix rock blocks. These properties are measurable by laboratory tests on cores and formation studies in the reservoir. This approach contrasts with a common trend in fractured reservoir simulation favoring the use of parameters to account for the matrix-fracture interaction; these parameters cannot be explicitly linked to the reservoir characteristics.

The presented formulation results in a system of three simultaneous integro-differential equations where the dependent variables are: the dephts of the gas-oil and water-oil contacts, and the pressure at the datum. Observed and calculated variables, obtained applying the model, are in good agreement throughout the forty-five years long production history of an actual reservoir that includes a period with null production, while all the wells were closed, that resulted in an unusual fluctuation of the variables.
The Development and Testing of a Sequential Semi-Implicit Four Component Reservoir Simulator
Authors: Watkins Robert William
Published: December 2007

This paper describes the application of the sequential, semi-implicit saturation formulation to a four-component, mixing parameter-type miscible flood reservoir simulator. The semi-implicit saturation formulation has greater numerical stability than an IMPES formulation.

Furthermore, a comparison was made between results obtained with this simulator and a fully compositional simulator. When consistent fluid descriptions were used, results predicted by the two simulators for primary production, waterflooding, and miscible gas drive were in excellent agreement. Under conditions where significant amounts of free hydrocarbon gas existed, the mixing parameter model predicted more optimistic but qualitatively similar reservoir performance.
A Simulation Study of Detergent Flooding in a Vertical Cross Section
Authors: Cruz Dominguez-V Guillermo , Dougherty Elmer L. , Handy Lyman L.
Published: December 2007

A two-dimensional, fully implicit, numerical model for simulating detergent flooding is presented. The model considers the typically observed relation between detergent concentration in the water phase and interfacial tension, with this relation exhibiting a strong minimum at the critical micelle concentration. Interfacial tension and relative permeability are handled via a relationship developed from recent laboratory studies at the University of Southern California. The results obtained to predict effect of various parameters on oil recovery, from a system already waterflooded are presented. Parameters considered include location of injection interval, slug size, surfactant concentration, oil viscosity and injection rate.
Development of a Complicated Fault-Block Oil Field by Waterflooding
Authors: Chengguo Ma , Shirong Shuai , Yu Jin
Published: December 2007

The oil field is characterised by multiplicity of faults that cut the field into small blocks. Development units are divided into three classes according to the amount of natural energy. Insufficiency of natural energy is the main feature of development of the field which dictates the application of waterfloding in time to replenish energy. The point is emphasized that different types of units are to be differently treated in the maintenance of energy by flooding in respect to the level of pressure to be maintained and the appropriate time for the start of flood. A comparative study of different types of flooding is also made.
Reducing the Drag Force of the Multiple Phases Flow in Gathering Lines by Injecting Demulsifiers at Wellhead
Authors: JianZhong Huang
Published: December 2007

This paper describes the laboratory experiments on two phase oil-water emulsion. A technique of continuous injection of chemicals at the wellhead to break the emulsion and to reduce tne resistance in the \ill\ is suggested.

This method can be used at tne water cut production wells without heating, thus reducing energy consumption and production costs.
The Effects of Various Parameters on the Thermal Stresses in the Pipe Bends of Underground Pipelines
Authors: QiangKang Cai , YingMin Lü
Published: December 2007

The effects of various parameters on the thermal stresses in the pipe bends of underground pipelines have been investgated by the finite element method. According to the results of calculation, many graphs have been drawn to show these effects. It has been found that among the various parameters, the ratio of the radius of curvature of the bend to the outside diameter of the bend, the angle of the bend and the lateral soil pressure acting on the pipeline are the most important ones.
Mechanism of Tertiary Oil Recovery by Aqueous Chemical Flooding
Authors: Kamath Krishna I. , Zammerilli Anthony M. , Comberiati Joseph R. , Taylor Billy D. , Slagle Franklin D.
Published: December 2007

The tertiary recovery of oil by chemical flooding is an admittedly complex process involving both micro and macroemulsions. The work reported here suggests from fundamental considerations of theory, operation and economics that in situ emulsification of the immobile residual oil (and mobile secondary oil) in the petroleum reservoir and its transport as such to the producing well is feasible and has many advantages over miscible processes. These include freedom from mobility control and ultralow interfacial tensions that call for substantial chemical outlays. Arguments are presented in support of this view with tertiary oil recovery data obtained from Berea core floods using cosurfactant-free aqueous solutions of two hydrocarbon sulfonates differing substantially in their solubility in water. A brief discussion of pertinent EOR methods is given, emphasizing the occasionally obscured but significant distinction, from an EOR-perspective, that exists between the mobile (secondary), and immobile (tertiary) components of the reservoir oil targetted by these processes.
Abstraction of Sulfonates and Dodecane by Alumina
Authors: Viswanathan K. V. , Somasundaran P.
Published: December 2007

Investigation of the effect of oil on the adsorption of surfactants on reservoir rock minerals as well as the uptake of oil by the solid in the presence of surfactant is important for micellar flooding recovery systems. In the present study, the effect of oil on the adsorption of isomerically pure n-Na dodecylbenzene-sulfonate and n-Na decylbenzenesulfonate on alumina and the uptake of oil by the solid were determined as a function of surfactant concentration, ionic strength and temperature.

While the oil was found not to affect the sulfonate adsorption appreciably under experimental conditions studied, the uptake of oil as a function of sulfonate exhibited a decrease and in some cases followed by an increase. The results are discussed in terms of surfactant micellization and salting out, co-adsorption of oil at the solid/liquid interface and the solubilization of oil in micelle.
The Apparent Viscosity Of Power-Law Fluids And Its Application In Polymer Drive Simulations
Authors: Van Domselaar Hans Robbert
Published: December 2007

A new equation to describe power-law fluid viscosities in porous media is proposed. This equation is used in a simple mathematical simulator to test current theories and ideas on polymer drive.
Oil Shale And Shale Oil
Authors: Crabtree E.H.
Published: December 2007

There has been so much written and there have been so many addresses and technical presentations on oil shale given at various meetings during the last few months that it is difficult to present anything new. Even to summarize the history, the current status, the problems, and the potential of the industry would require much more time than we have today. So about all I can hope to do is to present some of the highlights, knowing that some of these will be a repetition for many of you, but hoping that I can give you members of the mining industry a perspective of what the oil shale industry is today and where it will probably be tomorrow.

For us who have spent our professional lives in the mining industry, oil shale is unique. We know where it is; we don't have to hunt for it. It is measured in hundreds of feet of thickness, in thousands of square miles of area, and in billions of barrels of oil content. The problems are technological and legal. How will be the best way to mine the shale? How will be the best way to extract the oil? Where will it be marketed? What will it cost? What will be the leasing and tax policies of both the State and Federal governments?

One of the many questions asked today is why do we need shale oil? With a large portion of our domestic crude production restricted, and with limitations on imports from large foreign sources, won't we have all the conventional petroleum required? The answers to these questions are more questions. Can we afford to be dependent upon foreign supplies? Are our domestic reserves sufficient for our expanding needs? Will the cost of finding new reserves eventually exceed the cost of producing shale oil?

Recently, Assistant Secretary of the Interior John Kelly quoted President Johnson as follows: ". . . In the remainder of this century urban population will double, city land will double, and we will have to build homes, highways, and facilities equal to all those-built since this country was first settled. So in the next 40 years, we must rebuild the entire urban United States."

If this is true, a tremendous increase in sources of energy will, of course, be required. With our present reserves of petroleum and coal, and atomic energy being rapidly developed, no shortage is anticipated.
The Dissolution Effects of CO2-Brine Systems on the Permeability of U.K. and North Sea Calcareous Sandstones
Authors: Ross Graham D. , Todd Adrian C. , Tweedie John A. , Will Andrew G. S.
Published: December 2007

Dissolution could be a serious problem in the operation of a carbon dioxide flood on a carbonate cemented sandstone. Laboratory core flooding experiments under reservoir conditions demonstrate the effect of the dissolution and the significance of textural properties of the rock. Core flood tests carried out on North Sea core material show similar permeability alteration and effluent concentrations both as a result of channelling and of total dissolution. The presence of residual oil delays the dissolution process. The textural heterogeneity in real rocks make it difficult for existing acidization models to be applied to the interpretation of the laboratory results.
Modeling of Gas Injection in Fractured Reservoirs
Authors: Eica Aniefiok Sunday , Ershaghi Iraj
Published: December 2007

Gas injection into a naturally fractured reservoir is simulated using a mathematical model which includes convective and capillary forces. The study conducted for both a single matrix block and a stack of matrix blocks shows that recovery of oil from low permeability matrix can be optimized by commencement of gas injection early in the productive life of the reservoir. Furthermore, by manipulating the pressure distribution in the system through temporarily shutting in the production wells when GOR's are high, the ultimate oil extraction from the matrix blocks may be improved.
Quality Assurance — No Margin for Error
Authors: Thomas R. L. , Smith C. F. , Grant W. D.
Published: December 2007

Quality Assurance (QA), a critical component of a hydraulic fracturing treatment, must be performed prior to and during the job. Failure to follow QA procedures may result in added well costs and poor production. It begins during the design and ends after the completion of the job. The importance of Quality Assurance has been magnified in recent years due to the increased size and complexity of fracturing treatments. It is a tool used to ensure that fluids, proppants and equipment meet the increased demands placed upon them.

This paper discusses several steps taken in order to provide Quality Assurance. An explanation of procedures used during the job design and prior to the job is given. A discussion of procedures and troubleshooting techniques used prior to and during the job is also presented. The sensors and computer system used in order to monitor QA data are also discussed.
Bottom-Hole Stresses in a Well Bore
Authors: Deily F.H. , Durelli A.J.
Published: December 2007

Bottom-hole stresses in a well bore have been calculated using the results of photoelastic analyses. Boreholes in the earth were simulated in marblette cylinders. Three hole bottom contours were studied, including flat and semi-hemispherical bottoms. Two types of surface stresses were found at or near the hole bottom, meridional and circumferential. Stress concentration factors are presented graphically as a function of overburden (geostatic) and well bore (hydrostatic) pressures. For well bore and overburden pressures encountered in normal mud drilling, radial stresses on a flat bottom hole may change from 74 per cent of overburden at the center to 192 per cent near the hole wall. Knowledge of triaxial states of stress across the hole bottom will enable a better understanding of rock strength under borehole conditions.

The purpose of this study is to determine bottom hole rock stresses in terms of overburden pressure and borehole pressure. The knowledge of such stresses will enable better future prediction of rock strength and drilling action.

Since hole end geometry is complex, serious mathematical difficulties are encountered in solving this problem. Consequently, the use of three dimensional photoelastic techniques was chosen to achieve these objectives. Of primary concern in the photoelastic study was the determination of the two principal stresses in a plane tangent to the surface of pressurized boreholes. Principal stresses act on planes in which no shear exists.
Petroleum Engineering Manpower Supply
Authors: Dorfman Myron H. , Harkins H. B. (Burt)
Published: December 2007

The supply of Petroleum Engineers within the U. S. has shown an exponential growth during the last decade due to increases in the price of petroleum and concommitant demand for engineers in the petroleum industry at all levels of activity. Schools currently have very large enrollments; many lack sufficient faculty and facilities to adequately handle the large loads. Recent uncertainty in long range forecasting of petroleum demand, coupled with uncertainty in the price of oil due to turmoil in the Middle East and the discovery of additional large reserves of petroleum as a result of increased drilling, has led to a decline of approximately 25% in the price of crude oil on the spot market and subsequent reductions in drilling in 1982 from a high of 4,500 rigs in the U. S. to 2528 rigs by August 31, 1982; a reduction of 44% this year. This reduction in activity will be reflected in reduced job opportunities for many new graduates in December 1982 and in 1983, and the "pipelines" within the schools are filled with students in expectation of good jobs in the private sector of the economy. Since Petroleum Engineering departments maintain a close tie with industry, it is essential that some balance be maintained between supply and demand, so as to try to prevent a glut of engineers descending upon the market. Steps are underway at many schools to reduce enrollments by a variety of methods at the present time. An upturn in demand in petroleum prices may serve to mitigate the problem within the next two years, but a long-range interchange between industrial hiring forecasts and universities is essential in planning for the future.
The Field Development of Cognac (Mississippi Canyon 194) Field: A Case History
Authors: Nations J. F. , Speice C. B.
Published: December 2007

The drilling operations portion of the field development of Project COGNAC (Mississippi Canyon Block 194 Field) was completed in August, 1981, six months ahead of schedule. Activities conducted during the "drilling cycle" included drilling and casing 61 wells and completing 36 wells for production before rig down. The wells developed a four-block, multizone accumulation from a dual rig platform set in a world record 1025 feet of water.

The case history of the field development of COGNAC documents the geological and drilling planning/experience unique to a project that included: Two drilling rigs operating simultaneously yet independently from one platform;Potential problems associated with shallow wellbore interference. Accidental well intersections were avoided despite a high interference potential;High angle/long reach wells. Thirty-four (34) of the 61 wells had average drift angles in excess of 50°. Wellbore drifts up to 7850 and 9790 feet at true vertical depths of 7922 and 8660 feet respectively were accomplished and casing run to total depth; andSimultaneous producing while drilling (PWD) operations. Oil production from the platform began approximately two years before the end of drilling activities.

The planning and experience summarized in the paper should be valuable to Geological and Drilling Engineers involved in development planning of fields located in the offshore environs.
Economic Considerations Affecting Steam Flood Prospects
Authors: Keplinger C.H.
Published: December 2007

Steam stimulation results have been given "glamorous" coverage in the oil and financial press in recent months. One article spoke of steam injection as a "tonic" for tired oil fields, a "thermal Geritol" which thins down viscous crude and helps stimulate the production of oil. Some isolated spectacular results have indicated very large initial increases in production.

An attempt has been made to collect well performance data of steam soak operations for economic appraisal. Twelve operators were contacted and I am grateful and appreciative of their cooperation. Not all those contacted furnished data, but they were helpful in their encouragement to prepare the paper. Some producers have kept their steam injection operations quiet while learning the technology of steam stimulation. However, for this paper, the operators who made available their stimulation results furnished well performance data of the heavy oil fields of the San Joaquin Valley of California. The attached map, Plate I, shows the location of thermal steam projects in California together with the names of the operators in each field.

In evaluating the economics of steam "soak" recovery, there is no escaping the uncertain task of peering into the future based on available past performance. A detailed forecast is a massive job and falls outside the scope of this paper because much of the available data on performance has not been released by operators; nevertheless, it is intended to treat the subject in the broadest of terms with the limited operational data in order to identify the main economic considerations.

Successful operations are dependent on initial and repeated productive response to steam injection, productive trends after each steam soak, optimum spacing and steam costs.

At this time steam flooding will be briefly described and defined. There are three primary methods of using steam to increase oil production. Plate II shows these three induced production methods by steam injection.
Filtration of Gas on Offshore Platforms With Special Reference to Sand Removal and Slug Catching
Authors: Forsyth Donald F. , Chamberlain Neville P.
Published: December 2007

Multicyclone designs have proved effective in reducing the cost and weight of high pressure gas wellhead separators. This is achieved with improved efficiency and turndown range over other types of separators. Erosion problems and their solution are discussed.

Similar savings in size and weight with improved efficiency and turndown are also being achieved in offshore slug catching separators.
Modified In-Situ Retorting Results of Two Field Retorts
Authors: Berry Kay L. , Hutson Roy L. , Sterrett John S. , Knepper Jay C.
Published: December 2007

Rio Blanco Oil Shale Company (RBOSC) has designed, constructed and processed two Modified In Situ (MIS) retorts at Tract C-a using newly developed techniques for rubbling, ignition and operation through surface drill holes. Retort Zero was ignited in October 1980, nominal dimensions 30' × 30' × 165' (9 × 9 × 50 meters), oil yield was 1,876 barrels (298,300 liters). Retort One was ignited June 1981, nominal dimensions 60' × 60' × 400' (18 × 18 × 122 meters), oil yield was 24,444 barrels (3,886,000 liters). RBOSC's MIS method was proved very successful; ignition was achieved in less than 36 hours, average front advance rates were 2.7 and 3.0 ft/day (.8 and .9 meter/day) and oil yields were 68 percent of Fischer Assay, close to model predictions for both retorts. This paper will describe conceptually the MIS method developed by RBOSC and give the process results. Details of how the results were achieved are proprietary.
Cycles of Crisist, Seasons of Glutt … Wheret Do He Go From Here?
Authors: Lee James E.
Published: December 2007

From Maine to Texas, there are a couple of cliches you'll hear if you ask about the weather. One of them goes, "If you don't like the weather around here, just wait a little while, and it will surely change."

It strikes me that much the same thing might be said about market and supply conditions in the oil business.

Just think, for example, of the extraordinary changes in the oil market over the recent past. only a few years ago, the national scene was characterized by shortages and rumors of shortages, by vaulting prices and plunging spirits … amd by presidential lectures about a new french import called "malaise".
The United States Petroleum Industry Investment and Capital Markets Outlook : A Chase Perspective
Authors: Carey James H.
Published: December 2007

Good afternoon, ladies and gentlemen.

I'm particularly pleased to be with you today -- and not only because it is an honor to speak to such a pivotal group of professionals in what is clearly one of the world's most essential industries.

Before discussing the present and future funding of the U.S. petroleum industry, I want to define briefly for you the economic environment in which we believe the industry will be operating through the balance of the decade.
A Method for Selecting Potential Infill Locations in the East Texas Cotton Valley Tight Gas Play
Authors: Tison Joel K. , Agarwal Ram G. , Rosepiler Michael J. , Schlottman Bernard W.
Published: December 2007

To fully develop producing acreage in low permeability gas plays, infill reserves must be assessed and development areas must then be identified. Currently in Texas, at least 25 major tight gas plays have been recommended for tight gas formation designation to the Federal Energy Regulatory Commission, and at least 10 of these have been approved for incentive gas pricing. In the East Texas Basin alone, there are at least 10 major field areas in a tight gas sand play. All of these plays and fields within them will require study to determine the feasibility of infill development. A technique for selecting potential infill locations is outlined below.

Critical reservoir and fracture parameters are investigated by determining each parameter's effect on the incremental reserves from an infill well. The most important parameters are: formation flow capacity, hydrocarbon pore volume, fracture length, and pay continuity.

These parameters are used to obtain simulated rate data for well groups from a tight gas reservoir simulator. Recoverable gas is determined from a plot of the simulated data as scalar curves relating well rate and cumulative production data to time, normalizing the curves to the above critical parameters. Potential infill reserves are assessed for East Texas Cotton Valley wells using the results from the above curves in an expression for incremental infill reserves. The variation of incremental reserves with fracture length for varying permeabilities is investigated to obtain an economic limit on incremental reserves for a general area and to determine the range of permeabilities justifying reduced well spacing.

This two-well analysis approach assumes separate, non-interfering drainage blocks and may introduce error in high permeability areas. Moreover, this analysis technique assumes no time delay in drilling the infill well on a unit. Static pressure measurements in the first infill wells must be obtained to evaluate potential interference as well as gain experience in drainage radii for the original wells on a unit.
Onsite Analysis of Sucker Rod Pumping Wells
Authors: Kramer M. J. C. , Martin J. D. , Neely A. B.
Published: December 2007

Shell Oil Company has developed a van-mounted minicomputer system that determines surface and downhole rod pumping performance at the well site using the Sucker Rod Diagnostic Technique. The benefits achieved, the reliability of both the hardware and software, and the number of systems placed in operation have far exceeded expectations. The system has proved to be a significant factor in the operation of Shell's rod pumping wells, as well as an effective training tool for both Engineering and Operations.
Field Testing the Fluid Rod Production System
Authors: Peterson Daniel G. , Brady Joseph
Published: December 2007

The Fluid Rod Production System introduces a new concept for the production of low volume wells. Utilizing production fluid or non-treated lease water as the power transfer medium, fluid power is transmitted from a skid mounted surface unit to a downhole stroker which directly actuates a standard API rod type pump.

This Fluid power is cyclicly applied and relieved at the surface unit to create a pumping action downhole. The fluid utilized for power transfer is contained in a small diameter tubing string and with the exception of a small amount of slippage downhole, remains in this string thus eliminating the need for a large fluid supply or fluid storage and treating facility.

Field testing now underway has demonstrated that the Fluid Rod Pump is a viable alternative for the production of low volume wells. Prototype system testing has been under way in Brea, California since October of 1981.

During that time the system has been tested at various production rates up to 155 BFPD and the optimization of components has been carried out. A production version of the system has been operating in Wilmington, California since June of 1982. This installation has demonstrated the versatility of the system by operating at an average of 20 BFPD in a well deviated 19° from vertical at the seating depth.
Surface Detection of Retort Gases from an Underground Coal Gasification Reactor in Steeply Dipping Beds Near Rawlins, Wyoming
Authors: Jones Victor T. , Thune Howard W.
Published: December 2007

A near-surface soil-gas geochemical survey was executed in conjunction with the Phase II experiment at the North Knobs, Wyoming, GR&DC-DOE UCG facility from July 22, 1981, through December 12, 1981.

The soil-gas detection method offers a unique new technique for locating potential gas leakage areas before any significant migration avenues can develop. This approach has the advantage over atmospheric measurements because the soil gases are not greatly affected by winds and other varying meteorological conditions; therefore a much lower level anomaly may be resolved.

One hundred and twenty-two, 18 foot deep permanent sites, based upon the local geology, were located and installed over the areas of both the previous Phase I and the current Phase II retorts. All sites were routinely monitored for methane, ethane, propane, i-butane, n-butane, ethylene, propylene, helium, hydrogen, carbon dioxide and carbon monoxide. Selected sites were periodically monitored for carbon disulphide, carbonyl sulphide, hydrogen sulphide and sulphur dioxide.

The survey demonstrates that residual gases from the Phase I burn are still present in the near surface and product gases generated during the Phase II burn were clearly evident. Maps are presented showing the areal distribution of these products during: (1) the pre-burn, pre-pressure period; (2) the air-pressured interval during system checkout; (3) the ignition and early burn period; and (4) the late-burn and early post-burn interval. These maps and the tabulated data indicate a recognizable surface response occurred 3-6 days after changes in the burn retort pressures. Product gases migrated into the near surface both vertically and laterally along well developed cross-joints and near-strike joint sets within the sandstones stratigraphically above the coal seam being burned. Additional leakage is probably associated with poor cementing of the casing in some of the deep boreholes. Casing leakage explains most of those anomalies located in the rock sequence stratigraphically below the coal. While throughout the survey abnormally high values were found in the near surface at many geochemical sites, ambient air samples routinely taken near those sites consistently had low values. It is concluded that a properly designed and operated UCG facility would not experience any adverse product gas leakage and would pose no hazard problems from either a safety or environmental point of view.
Fracture Orientation Analysis by the Solid Earth Tidal Strain Method
Authors: Hansont Jonathan M. , Owen Lawrence B.
Published: December 2007

A new practical method has been developed to estimate subsurface fracture orientation based on an analysis of solid earth tidal strains. The tidal strain fracture orientation technique is a passive method which has no depth limitation. The orientation of either natural or hydraulically stimulated fractures can be measured using either new or "old" static observation wells. Estimates for total compressibility and areal interconnected porosity can also be developed for reservoirs with matrix permeability using a combination of tidal and barometric strain analysis. Data acquisition requirements are modest and no surface instrumentation beyond pressure monitoring equipment is required. The tidal method has been successfully demonstrated at a naturally fractured geothermal field (Raft River) in Southeastern Idaho and at an oil field in Western Canada. Both case studies are described.
An Integrated Digital Well Logging System
Authors: Peressini R. J. , Howells A. P. S. , Fertl Walter H.
Published: December 2007

Basics of the SLAM Digital Combination Logging System are discussed including an overview which describes each of its major components; the computer-based surface data acquisition system, wellsite analysis software package, and the individual and combination measurement systems used with SLAM.

Combination logging runs that are possible with the SLAM system are presented to illustrate their application in a number of different geologic and borehole conditions. The advantages to performing combination logging runs are also discussed.

Log presentations available are illustrated to demonstrate methods for diplaying combination log data in usable formats.

Diagnostic programs and troubleshooting aids arc reviewed to demonstrate their ability to help predict when equipment is becoming marginal, and to minimize lost time due to equipment failure.

Standard methods for performing instrument calibrations are described, including techniques to perform master calibrations at the shop or wellsite, as well as before and after wellsite checks performed with instruments suspended over the borehole, or on the catwalk.
Risk, Stopping Rules, and the Economic Viability of Exploratory Drilling
Authors: Rankin Mark D.
Published: December 2007

The thesis put forth in this paper involves three refinements to the practice of using probability weighted outcomes, or "expected values", as a means of determining the economic viability of an exploration prospect. The first involves the introduction of Polya's distribution in the assessment of conditional probability. In addition, the effect of stopping rules as constraints to the ultimate extent of exploratory drilling is studied. Finally, implications relating to the effects of changes in economic and geologic variables on the levels of exploratory drilling are examined.
Production Scheme for Deep Water Hydrate Deposits
Authors: Rose Walter , Pfannkuch H. O.
Published: December 2007

There is substantial evidence that enormous natural gas hydrate deposits are entrapped in the bottom sediments underlying many of the deep waters that cover the earth, as well as in subsurface permafrost sediments of the polar regions. This paper addresses the important but largely ignored question of how to recover natural gas from the deep water bottom occurrences. The first problem is to gain access to the resource, the second to promote decomposition of the hydrate, and the third is to collect and bring the exsolved gas to the surface. A scheme assumed to be technically feasible involves the use of closely-spaced flexible hoses imbedded to protrude through the underside of the hydrate layer through which warm water can be circulated downwards and recovered gas brought upwards from and to surface floating platforms equipped with pumps, compressors, conversion facilities, storage vessels and pipeline manifolds.
The Austin Chalk—Drilling and Completion Techniques—Marcelina Creek Field Study
Authors: Betz Cynthia A.
Published: December 2007

Exxon Company, U.S.A. has spent considerable time and effort learning how to minimize formation damage in the lost returns prone and clay sensitive Austin Chalk formation. To date, Exxon has successfully drilled 24 Austin Chalk wells in the Marcelina Creek Field in Wilson County, Texas, utilizing a variety of drilling and completion techniques in an effort to determine the optimum method of drilling and completing Austin Chalk wells. This paper describes these different techniques and reviews actual results. Although Exxon has not concluded which drilling and completion technique yields optimum Austin Chalk wells in this field, this paper attempts to develop a correlation between well productivity and the type of drilling and completion technique used.
The Accuracy of Pulsed Neutron Capture Logs for Residual Oil Saturation
Authors: Schenewerk Philip A. , Knapp Roy M. , Fertl Walter H.
Published: December 2007

Pulsed neutron capture (PNC) logs have been used to determine residual oil saturations for many years. A previous study found that at low values of residual oil saturation (ROS) conventional PNC logging techniques did not have the accuracy necessary for enhanced oil recovery decision making requirements. Special log-inject-log techniques were developed in order to reduce the uncertainty in values of ROS measured with PNC logs.

A study of the uncertainty associated with ROS values determined with PNC logs was made using Monte Carlo simulation techniques. Field data was obtained from tests reported in the literature. Using a more realistic confidence interval of 95%, the expected accurace of the ROS values was found to decrease by at least a factor of two in all tests. Additional uncertainty introduced by the log-inject-log process was not modeled.
Development of Cotton Valley Gas in Carthage Field—Price Was the Key
Authors: Lyons Frank E. , Asseff George
Published: December 2007

Development of the Cotton Valley formation in East Texas has been stimulated by the economics of higher gas prices. The combined actions of the industry, Congress, the Federal Energy Regulatory Commission (FERC) and the Texas Railroad Commission (RRC) have added to the market gas reserves that were discovered in 1937, but were not economical to produce until the 1970's.

The Cotton Valley formation in Carthage Field, Panola County, Texas, (Figure No. 1) was first penetrated in 1937, and cores from that well indicated the presence of gas. Drill stem tests in 1944 confirmed the presence of gas in these deep, low permeability sands. The gas price then was $0.03 per MCF.

The first gas production was recorded in 1968, from one well, and by 1975, seven wells were producing. Gas prices had now increased to $0.62 per MCF. When the price of gas reached $2.49 per MCF in 1979, development increased rapidly with 117 new wells being drilled and completed that year, 86 wells in 1980 and 53 wells in 1981.

The drilling of these wells was a result of higher gas prices under the Natural Gas Policy Act of 1978 (NGPA), the "tight" gas classification by FERC on October 24, 1980, and Railroad Commission approval of 320-acre spacing on February 9, 1981, to permit additional drainage wells on the 640-acre units.

The price of gas is now over $6.00 per MCF, and more than 400 wells are producing from the Cotton Valley as development continues.
Ten Years of Handling CO2 for SACROC Unit
Authors: Gill T. E.
Published: December 2007

SACROC Unit initiated CO2 injection in 1972 for oil assisted recovery. Ten years of handling CO2 through the compression, pipeline, injection, and removal facilities has confirmed their original designs and has caused some changes for improved operations. The reader should gain an awareness of the complexities involved in handling CO2 and a perspective for better operating considerations in handling CO2 in the oilfield.
Planning and Development of the Northeast Purdy Springer CO2 Miscible Project
Authors: Brinlee Larry D. , Brandt James A.
Published: December 2007

A carbon dioxide miscible injection project is planned for the Northeast Purdy Springer reservoir. Injection on a WAG basis will begin in mid-1982. A description and overview of the events and activities leading up to the initiation of CO2 injection is described. Three years of planning and evaluation of the project began in 1977 and was followed by two years of field construction development. Incremental oil recovery is expected to be 16.8 million STB.
Installation of the Fulmar SALM and Storage Tanker
Authors: Gunderson R. H. , Coornbe J. G. B. , Lunde P. A. , Etheridge C. O.
Published: December 2007

The Fulmar Single Anchor Leg Mooring (SALM) permanently moors a converted tanker serving as a Floating Storage Unit (FSU) in the North Sea at Shell/Esso's Fulmar Field. The Fulmar storage and offloading system is the first such system installed in a rough weather area.

The installation of the SALM was unique, not by choice, but because of the requirements imposed by the nature of the system and by the environmental effects on the structure during installation. The SALM is comprised of very large, heavy structural components joined by mechanical articulations and connections. The size and weight necessitated that the connection of the FSU to the buoy be made offshore. The installation of the structure was weather sensitive, requiring the design of numerous "hold points" into the procedure; for instance, the SALM buoy acted temporarily as a gravity structure, being transformed finally into a pile founded structure.

The loadout and installation strained the capacity of both dockside and floating equipment and produced several new world weight records. Novel applications of conventional equipment were used for loadout and transport of the components, for rigging used to make the major offshore lifts and connection between moving assemblies and for the rapid slurry installation of the permanent ballast.

This paper describes the installation procedures along with the corresponding field experience. Data on rigging, lift weights, seastate limitations and schedule are presented for use by those who may be faced with a similar opportunity.
Interpretation of Postfracture Temperature Surveys
Authors: Wages Paul E.
Published: December 2007

This paper discusses the interpretation of temperature surveys for evaluating fracture treatments for gas wells in Southwestern Wyoming. In these wells, the treated intervals recorded higher temperatures than would normally be expected, making the interpretation of the survey difficult. The characteristics of this anomaly were investigated by running multiple post-fracture temperature surveys and a gamma ray log for locating radioactive proppant in one well.
Partially Hydrolyzed Polyacrylamides with Superior Flooding and Injection Properties
Authors: Argabright Perry A. , Rhudy John Stanley , Phillips Brian L.
Published: December 2007

Polymers have found widespread use for oil field applications. They play an especially important role in secondary and tertiary oil recovery processes as mobility control agents.1, 2 For a variety of reasons, not the least of which is cost effectiveness, synthetic polymers are favored over their "natural" counterparts - the polysaccharides. Of the multitude of synthetic polymers, partially hydrolyzed polyacrylamide (PHPA) is the most widely used in a spectrum of enhanced oil recovery processes.

PHPA reduces the mobility of displacement water in porous media (reservoir rock) by a combination of increasing its viscosity and reducing the permeability to water in accordance with the equation

For permeability reduction, a manifestation of polymer retention, to be a useful factor, its effect must be propagated uniformly throughout the reservoir. Unfortunately, the available PHPAs of commerce share a common shortcoming - face plugging. That is, permeability reduction is greater around the injector than at more remote distances in the reservoir. Face plugging dramatically reduces injectivity and consequently prolongs project life. In view of this property of the commercial products, a study was undertaken at our laboratory to develop a high performance PHPA that does not exhibit preferential permeability reduction in the near-wellbore region.
Pressure Transient Analysis of Wells in Very Long Narrow Reservoirs
Authors: Nutakki Ramagopal , Mattar Louis
Published: December 2007

In this paper, the radial and linear flow regimes in long, narrow channels were studied. The extent and duration of each regime was noted for a number of different dimensionless channel widths. Both "semilog" and "square root time" plots were made of the pressure transient behavior at the wellbore. These plots, as expected, showed radial flow (semilog straight line) at the beginning and linear flow (square root straight line) at later times. An abrupt change from radial to linear flow does not occur, rather there is a region where the pressure transient behavior closely approximates radial and linear flow at the same time.

An equation was derived for calculating the channel width, using the time where the semilog straight line ends. The linear flow regime in long, narrow channels can be precisely analyzed using existing linear flow equations, with the incorporation of a "pseudo-skin" factor, which accounts for the additional pressure drop due to the decreasing crosssectional area for flow as flowlines converge at the wellbore. Because of this additional "pseudo-skin" factor, log-log plots of the pressure transient behavior of long, narrow channels do not yield lines of slope one half (until time becomes very large), and hence these plots, which are often used to detect linear flow, should not be used.

The practical implications of this study are discussed as they pertain to production and drillstem tests. It appears that the end of the semilog straight line and the beginning of linear flow can be detected during the time that a drillstem test is conducted.