bluuebunny/crossref_metadata_2025 huggingface dataset:
A Study of Adsorption of Gases in Tight Reservoir Rocks
Authors: Satik Cengiz , Horne Roland N. , Yortsos Yanis C.
Published: December 2007

In this work, we studied adsorption in tight porous solids using both experimental and numerical methods. We conducted adsorption experiments for geothermal reservoir rock samples and studied the scanning behavior of the steam sorption hysteresis loop. The results of the sorption experiments show that temperature has an important effect on desorption, such that hysteresis becomes more pronounced as the temperature increases. Using a pore network model to represent porous media we investigated adsorption-desorption processes over the range of the relative pressures, highlighting in particular capillary condensation. The numerical model incorporates recent advances from density functional theory for adsorption-desorption in narrow pores (of order as low as 1 nm), which improve upon the traditional multi-layer adsorption and Kelvin’s equation for phase change and provide for the dependence of the critical pore size on temperature. Comparison of the numerical results with the experimental findings showed a good agreement. The hysteresis in the adsorption-desorption cycle is interpreted in terms of blocking of larger pores, where adsorbed liquid is allowed to but cannot desorb, by smaller pores containing liquid that may not desorb. The hysteresis also increases if the porous medium is represented as a fractured (dual porosity) system.
Pore-Network Studies of Steam Injection in Porous Media
Authors: Satik Cengiz , Yortsos Yanis C.
Published: December 2007

Conventional approaches in modeling steam injection (or other vapor-liquid flow) in porous media are based on relative permeability and capillary pressure formalisms borrowed from isothermal, two-phase flow. When phase change is involved, however, additional phenomena, such as heat transfer and condensation must be accounted for. In this paper, we present a theoretical and numerical study to test the validity of this approach. The theory predicts the existence of a compact pattern at conditions when heat transfer predominates. This regime is consistent with the very small residual saturations, typically observed in steam displacements. Heat transfer and phase change also lead to smaller values for the effective mobility ratio, Meff, and the capillary number, Ca. Such displacements can be portrayed in a three-dimensional phase diagram with coordinates Meff, Ca and StPe−1> where St is the Stefan number and Pe the Peclet number. A pore network simulator is next presented. Depending on the location in the parameter space, displacement patterns are shown to lie in the compact, percolation or viscous fingering regimes. The theory was found to be in general agreement with the numerical simulations. Observations from experiments in micromodels also support the general findings.
Three Phase Oil Relative Permeability Determination as a Key Point in the Evaluation of a Tertiary Gas Drainage Gravity Project
Authors: Chalier G. , Giry V. , Madaoui K. , Sakthikumar S. , Maquignon Ph.
Published: December 2007

For several years a dual energy gamma-ray absorption measurement apparatus has been routinely performing in situ three phase saturation monitoring during coreflood experiments in reservoir conditions. This paper presents this sophisticated equipment and the application of the technique to determine the three phase oil relative permeability at low oil saturations during a tertiary gas gravity drainage experiment. The oil relative permeability was thought to be a crucial point to validate the economic feasibility of this tertiary oil recovery process for a waterflooded reservoir in the Far East.

Using the gamma-ray absorption technique it was possible to visualize the fluid saturation distribution in the core as a function of the volume of gas injected. The production of tertiary oil by gravity drainage was put into evidence at the top of the core. The three phase oil relative permeability curve was deduced from the oil saturation profdes using an analytical calculation.

The experiment was finally correctly reproduced with a generalized compositional simulator, emphasis being put on the match of saturation profiles. A triphasic relative permeability model was then validated.
Water Control Diagnostic Plots
Authors: Chan K. S.
Published: December 2007

A new technique to determine excessive water and gas production mechanisms as seen in petroleum production wells has been developed and verified.

Based on systematic numerical simulation studies on reservoir water coning and channeling, it was discovered that log-log plots of WOR (Water/Oil Ratio) vs time or GOR (Gas/Oil Ratio) vs time show different characteristic trends for different mechanisms. The time derivatives of WOR and GOR were found to be capable of differentiating whether the well is experiencing water and gas coning, high-permeability layer breakthrough or near wellbore channeling.

This technique was applied on wells in several fields in Texas, California, the Gulf Coast and Alaska. Plots using the actual production history data determined the production problem mechanisms. Together with well tests and logs, the technique was used to select well treatment candidates and to optimize treatments to enhance the return of investment.
Waterflood Recovery and Fluid Flow Upscaling in a Shallow Marine and Fluvial Sandstone Sequence
Authors: Ciammetti G. , Ringrose P. S. , Good T. R. , Lewis J. M. L. , Sorbie K. S.
Published: December 2007

Detailed reservoir characterisation and modelling has been an active area of petroleum technology development for several years now, but incorporating and scaling up these geologic models into fluid flow and production simulations is a major challenge. The objective of this study is to properly incorporate all relevant levels geological heterogeneity identified in a detailed outcrop reservoir description into a flow simulation of an hypothetical reservoir. We apply the "geopseudo" upscaling methodology to the geological description of a shallow marine sequence exposed in the Book Cliffs. The study identifies which features are important for field-scale fluid flow and recovery for a waterflood.

A cross section waterflood flow simulation, using the geopseudo upscaling technique, was carried out on an interpreted cross-sectional panel through a portion of the Book Cliffs outcrop in Utah. The section consists of the following lithofacies: Undifferentiated Upper Shoreface deposits, Hummocky Cross Stratified sands, the Swaley Cross Stratified sands, Fluvio-Tidal Channel Sandstones and two units of Heterolithics. A grid block size of 10 metres by 1 metre was used, with two stages of upscaling to account for the effects of small-scale heterogeneities. The thin beds of shales were accounted for using vertical and horizontal transmissibility multipliers between grid blocks. Sensitivity runs were carried out to assess the relative contribution of different geological parameters to the waterflood performance.
Comparison of Flash Calculations in Compositional Reservoir Simulation
Authors: Wang Peng , Barker John W.
Published: December 2007

This paper compares several recent flash algorithms in the context of compositional reservoir simulation. We evaluate three reduced equation methods: 1) the 3-equation flash of Michelsen (1986), which applies only when all binary interaction coefficients (kij) are zero; 2) Hendricks and van Bergen (1992); and 3) Kaul and Thrasher (1993). We also evaluate: 4) the non-iterative flash (Stenby and Wang, 1993); and 5) the method of Young (1991). We find that these last two methods, which are similar in concept, work well for reservoir simulation where the flash must be closely coupled with the solution of the pressure equation, and where a good initial guess is generally available. The reduced equation flashes offer no significant improvement over these other methods; this is true even for the 3-equation flash which solves a simpler problem (with kij = 0).
Optimization of Pseudo-Component Selection for Compositional Studies of Reservoir Fluids
Authors: Joergensen M. , Stenby E. H.
Published: December 2007

Twelve different lumping procedures were compared with the objective of formulating a generalized set of rules for pseudoization of reservoir fluids. These twelve methods consisted of three different grouping methods, and four different property calculation methods.

The lumping procedures were tested by simulating phase equilibria and PVT experiments for three different synthetic fluids. None of the tested methods performed significantly better than others, but some of the methods proved to perform worse than the majority of the methods.

It has been found that most experiments can be simulated with a reasonable accuracy (deviations less than two percent) when eight or more pseudo-components are used in the fluid description.
An Algorithm to Predict Pressure and Temperature Profiles through a Coiled Tubing.
Authors: Pilo S.
Published: December 2007

The scope of this work is to develop an algorithm to predict the temperature and pressure profiles in a compressible flow through a coiled tubing, taking into account both friction losses and heat transfer simultaneously. The algorithm combines the theory of gas dynamics (heat transfer process) and thermodynamics (energy balance) to predict pressure, temperature, density, velocity and Mach number profiles for either horizontal, inclined or vertical strings.The results of the algorithm were compared with the Cullender & Smith method, which is the standard correlation used for downward gas flow calculations. A strong agreement between them was obtained. The algorithm presented allows more reliable results because it only needs for start-up, gas data that is usually very precisely known in real conditions.
Filtration Control, Mud Design and Well Productivity
Authors: Leerlooijer K. , Kuijvenhoven C. A. T. , Francis P. A.
Published: December 2007

Filtration control has a considerable impact on drilling fluid properties & performance, on drilling costs and on well productivity. The requirements for filtration control, with regard to optimisation of the various stages of drilling a well, are ambiguous. This is largely due to the lack of understanding of the functionality of the mud components and on imprecise definition of demands.

Multi-Core Dynamic Filtration equipment has been designed to study static- and dynamic filtration (including spurt loss conditions) and assess their effect on return permeability for up to 4 core samples at a time. Several core samples in one experiment will enable us to evaluate the effect of permeability variation on clean-up efficiency. In another development, equipment has been designed for continuous measurement of cake thickness during filtration.

Polymer systems have been identified that effect acceptable fluid loss without solid particle additions. Apparently, the micelles formed have the dual functionality of solids to plug the pores and polymers to reduce cake permeability. This line of investigation may have potential in the development of truly solids free drilling fluid systems based on high density brines (e.g. Formates).
Effects of Various Parameters on Perforation Plugging and Perforation Cleanup
Authors: Han Liqun , Peden Jim M. , Ford John
Published: December 2007

Formation damage caused by kill fluids invasion and filter cake deposition in the perforation tunnel has rarely been addressed in the scientific literature. In this paper, a systematic experimental program using CaCO3-HEC slurry to kill perforated wells is presented. The perforation target is simulated using a cylindrical core with a drilled perforation, and borescope has been used to observe the distribution of filter cake in the perforation tunnel. Important parameters affecting perforation plugging and cleanup have been identified. The effectiveness of perforation cleanup methods, such as backflush and backsurge have been studied and the mechanism of filter cake removal investigated.

Experimental results show that among the various damage parameters investigated, only core permeability and fluid viscosity have big effects on Perforation Flow Efficiency (PFE), which is the comparative flow capacity of a damaged perforation to that of a clean perforation. Perforation Flow Efficiency decreases with increasing permeability.

The mechanism of filter cake removal strongly depends on the perforation cleanup techniques. When backflush is used to clean the plugged perforations, a threshold differential pressure has to be reached before flow can be initiated and a minimum volume of fluid must be flowed to achieve optimum PFE. Depending on the damage and cleanup conditions, plugged perforations may be partially or completely cleaned by backflush. Sequential backflush is advantageous over single constant rate backflush for high permeability core, where matrix damage is severe. Increasing backflush rate increases PFE. When backsurge is used, all the filter cake deposited can be removed instantaneously, and the PFE obtain is very high. Backsurge pressure is more important than backsurge volume.

The results obtained in this study will be very helpful in the design of kill pills and the design of perforation cleanup methods in the field.
Stability of Proppant Pack Reinforced with Fiber for Proppant Flowback Control
Authors: Romero J. , Feraud J. P.
Published: December 2007

A new method has been developed to prevent proppant flowback from a propped hydraulic fracture. The method consists of mixing the proppant with fiber elements before pumping the proppant into the fracture. The results of an experimental program, in which the goal was to better understand the mechanics of the reinforcing fiber on the proppant pack, are presented. The effects of fiber and sand properties on sandpack strength have been studied for an optimal use of the fiber. A macroscopic model has also been developed based on fiber and proppant properties. Laboratory tests on proppant with a low fiber content indicate a favorable agreement between the model prediction and the flowback tests.
Assessment of Formation Damage using Artificial Neural Networks
Authors: Kalam M. Z. , Al-Alawi S. M. , Al-Mukheini M.
Published: December 2007

Artificial neural network (ANN) models are designed to emulate human information processing capabilities such as knowledge processing, speech, prediction and control. The ability of ANN systems to spontaneously learn from examples, reason over inexact and fuzzy data, and provide adequate responses to new information not previously seen, has generated increasing acceptance for this technology in the engineering field and resulted in numerous applications. A preliminary investigation into the use of this novel technology is presented towards predicting formation damage by quantifying wettability and two-phase relative permeability of oil reservoirs.

An artificial neural network model based on the Back Propagation technique is trained with a number of variables from experimentally established relative permeability (relperm) curves. The reservoir core input data covers an extensive range of porosities and permeabilities from different lithologies having diverse wettabilities. The trained model is then tested with only a couple of easily obtainable input variables such as the Swc and Sor and predictions are made on the wettability and relperm curves. A change or shift in the relperm curves is associated with changes in wettability, and perhaps to formation damage in the drilling process.

The wettabilities of the rock-fluid system are predicted to within 90 % of the experimentally determined values. The relperm curves, particularly the end-points are predicted to within 85 % of the measured results. The accuracy of the predictions are significantly enhanced with model training using more precise reservoir data and better defined formation lithologies. Neural networks have immense potential in predicting relperm curves and thereby assessing formation damage in reservoirs.
Measuring Hydraulic Fracture Width Behind Casing Using a Radioactive Proppant
Authors: Reis J. C. , Fisher K. , Holcomb D.
Published: December 2007

Knowing the width of a hydraulic fracture behind casing can be useful in evaluating bodi reservoir performance and fracture design methods. This paper presents a method to obtain the widths of hydraulic fractures behind casing using radioactive, isotope-traced proppants. A tool-specific relationship between die gamma ray flux detected in a wellbore and the fracture width was developed using Monte Carlo simulation of gamma ray transport around a wellbore. This method provides fracture width estimates with a vertical resolution of about one foot. The method has been successfully used in the field and compares favorably with other methods for evaluating fracture widths.
Formation Damage Issues: Implications of Some Detailed Observations Using Analytical Transmission Electron Microscopy (ATEM)
Authors: Hill P. I. , Hughes C. R. , Issac K. P.
Published: December 2007

Solids characterisation forms an integral part of many studies related to petroleum engineering, e.g., coreflood evaluation assessment of fines migration and characterisation of precipitates; and is often completed using routine analytical methods such as Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD). These methods, however, cannot provide sub-micron detail of morphology and chemistry of solids and cannot be applied readily to characterise non-crystalline solids or solids present in low quantities. In this study, ATEM has been applied to examine solids isolated from produced fluids from an oilfied. The method has the potential to give early indication of production problems like sands production and scaling. It has also been used effectively to characterise scale inhibitor precipitates, which are non-crystalline, from corefloods and ‘batch’ experiments. Although ATEM cannot be viewed as a routine method since it requires specialised equipment and expertise, it can provide critical information.
Pyrobitumen Induced Formation Damage Problems
Authors: Shaw J. C. , Tsuen R. , Leggitt S. M. , Schramm L. L. , Rao D. N.
Published: December 2007

Pyrobitumen is a black solid insoluble carboniferous deposit derived from thermal degradation of hydrocarbons. Although the organic material has been observed in carbonate rocks world-wide, very little is known about its effect on some basic rock properties such as porosity, permeability, wettability, and potential for formation damage. All of these properties play significant roles in hydrocarbon recovery processes.

In this study, the amount and distribution of pyrobitumen were determined using a newly developed ashing method. Potential formation damage, which can be caused by entrainment of pyrobitumen during waterflood, oil production and acid stimulation, was examined using coreflood experiments. Electrophoretic mobility measurements and surfactant adsorption coreflood experiments were performed to study the effects of pyrobitumen on the surface properties and adsorption behaviour of these carbonate rocks. The effect of pyrobitumen on the wettability of carbonate rocks was investigated in the contact angle experiments.
Some Mechanical Aspects of Formation Damage and Removal in Horizontal Wells
Authors: Byrom T. G. , Coulter Gerald R.
Published: December 2007

This paper examines some mechanical aspects of formation damage as they apply uniquely to horizontal wells. First a seldom recognized phenomenon of mechanical damage due to drill string rotation is presented along with a method for estimating the extent of the damaged area. Next, the invaded zone is examined in some simple examples to ascertain qualitatively the geometry of the invaded zone due to varying exposure times of different parts of the horizontal section during drilling. The relative time scales between exposing new hole with the drill bit, the invasion rates into the formation, as well as the changing differential pressure in the horizontal annulus are incorporated into a simple model to determine the effect of changing annular pressure while drilling. Finally an inexpensive means of mechanically achieving zone isolation for damage removal treatments in unconsolidated zones is presented.
Viscous Fluids Provide Improved Results from Hydraulic Fracturing Treatments
Authors: Rosene R.B. , Shumaker E.F.
Published: December 2007

Improved recovery of oil and gas is possible with the use of highly viscous fluids in the hydraulic fracturing process. These are water or oil base gels that help create wider fractures than is possible with the so-called conventional fluids. This allows the placement of additional quantities (concentrations up to six pounds per gallon or more) of highly permeable propping agents in the fracture.

Guar gum, cellulose derivatives and synthetic polymers may be chemically modified to produce the thick gels that have viscosities in produce the thick gels that have viscosities in the 1000 to 20,000 centipoise range. Chemical breakers are added to assure adequate viscosity reduction after the treatment.

The oil-base gel is the latest development representing the introduction of new ester systems that can crosslink in refined oils such as kerosene, diesel oil, and low boiling aliphatic hydrocarbons.

Field results with these viscous gels are summarized. Specific case histories are examine to show improvement over other methods of stimulation.

Introduction

Since the advent of hydraulic fracturing as a well stimulation tool, a variety of fluids and treatment methods have been proposed and used to improve well productivity. Fluids used in this process over the years include: water, lease oil, process over the years include: water, lease oil, refined oil, water-oil emulsions, acid-oil emulsions, gelled oil, gelled water, and gelled acid. A recent development has been the introduction of thick fluids for hydraulic fracturing. These can carry higher concentrations of propping Agent, and they also produce wider fractures allowing for increased fracture conductivity. Low friction pressures while pumping, even though the fluids appear extremely viscous, allow the treatments to be performed at reasonable injection rates. This paper describes four of these fluid their characteristics, and treatment results that demonstrate the effectiveness of this approach to hydraulic fracturing. These fluids are:

(1) crosslinked guar gel;

(2) crosslinked cellulose;

(3) high concentration synthetic polymer; and

(4) an oil base gel.

Heavy refined oil-water dispersions were recently described by Kiel.

While the volume of fluid employed in hydraulic fracturing treatments has increased markedly, the flow capacity of the fracture has remained relatively constant. In many cases, the formation can feed the fracture faster than the fracture can transmit fluid.
WEMCO Depurator TM System
Authors: Bassett Glen M.
Published: December 2007

Introduction

The meaning of the word depurate is "to purify or cleanse"; therefore, a depurator is one which purifies or cleanses. Depurator is the name given purifies or cleanses. Depurator is the name given to the four cell flotation system, WEMCO TM Depurator System, which is manufactured by WEMCO Division of Envirotech Corporation.

The Depurator System is a natural aspirating, shear force flotation cell that has been designed for use in hazardous locations in the petroleum industry. The primary function of the Depurator System is to reduce the oil content in oily waters. In most cases, with chemical aid, the oil content con be reduced to acceptable limits such as 20 ppm oil or less.

ORIGIN

The WEMCO Depurator System originated from the WEMCO Fogergren flotation cell which is used in the benefication of ore in the mining industry. The WEMCO Fogergren is a single cell flotation unit which has been used for years; as a matter of fact, more than 15,000 WEMCO Fagergren flotation cells are presently in use. Other than the principle of self air inducement, the similarity just about ends. The WEMCO Depurator System operates with four cells in series which are completely enclosed, and explosion-proof motors; whereas the WEMCO Fogergren is an open cell which does not require explosion-proof motors. Also, the tank design is different. The Fagergren is designed for solid-liquid separation and the Depurator is designed for liquid-liquid separation.

Questions have arisen regarding how the WEMCO Depurator System came about as for as the petroleum industry is concerned, and what the need is for this equipment. First, the market was developed by federal state and local agencies that began to enforce and regulate the discharge of water to open ditches, pits, ponds, lakes, rivers and oceans. In most areas the ponds, lakes, rivers and oceans. In most areas the maximum oil content allowed in effluent waters is 20 ppm. To meet this demand, a process was necessary ppm. To meet this demand, a process was necessary that would be both efficient and economical. Therefore, the market is there for any process meeting these requirements; the WEMCO Depurator System does.

The next question was, how did the use of the WEMCO Depurator System come about for this purpose? It just so happens that during an equipment exposition in 1968, a representative for the Tretolite Division of Petrolite Corporation saw a Fagergren bench model on Petrolite Corporation saw a Fagergren bench model on display. After finding out that the Fagergren was used in benefication of ore, questions and interest developed into a program to determine if the Fagergren could be useful in effluent water clarification.
Numerical Simulation of Borehole and Formation Temperature Distributions While Drilling to Total Depth
Authors: Schoeppel Roger J. , Bennett Richard E.
Published: December 2007

A method was developed to model numerically the unsteady temperature distributions in a circulating drilling fluid and the surrounding formation. The model was based on a set of fourth-order partial differential equations describing heat flow by forced convection in the wellbore and by conduction in the adjacent formation. Finite-difference representations of these equations were formulated implicitly, and the resulting algebraic equations solved by modified methods of Gaussian elimination. A numerical error analysis was made to determine the accuracy of the method. Computer simulation time for solution of the numerical model is reasonably short. The method was found to provide an accurate solution to the problem of provide an accurate solution to the problem of predicting nonsteady temperature distributions predicting nonsteady temperature distributions associated with drilling of a well. It can be used to study the physical system in detail and is capable of simulating real systems that have heterogeneous and/or time dependent properties.

Introduction

A knowledge of subsurface temperatures is of prime interest to geoscientists and geotechnologists alike. Geologists are interested in subsurface temperatures to better understand geomechanisms such as diagenesis of sediments, formation of hydrocarbons, genesis and emplacement of magmatic formation of mineral deposits, and crustal deformations. Geophysicists are interested in studies of subsurface heat flows. Petroleum engineers require a knowledge of subsurface temperature to design properly the drilling and completion programs and to facilitate accurate log interpretation. Mining engineers need this information to assess the economic value of mineral resources. For geothermal engineers, this knowledge is valuable in the proper exploitation of geothermal resources.

Recognizing the usefulness of subsurface temperature data, a geothermal survey of North America aimed at preparing a regional geothermal gradient map was initiated by the AAPG. It was known that equilibrium temperature data were not readily available for most of the continent. Therefore, an engineering recourse to use near equilibrium logged temperatures was proposed.

Mathematical equations describing borehole heat transfer during and after drilling are available in the literature. However, neither a direct nor an approximate solution has been reported. Accordingly, it is the objective of this paper to present a numerical method capable of modeling accurately the nonequilibrium temperature distribution in a borehole.
Early Planning for Gas Storage Pays Off - A Case History of Kentucky's Largest Gas Field
Authors: Griffith Howard D. , Rinehart Richard D.
Published: December 2007

This paper traces the transition of a natural gas field into a major gas storage system" Texas Gas Transmission Corporabon's programs to facilitate the transition programs to facilitate the transition early in the life of the field are shown. A detailed geologic and engineering analysis of the reservoir which has played an important role in the development of storage is also presented. presented. The reservoir in this study is the Midland gas field which is located in Muhlenberg County, Ky. on the southeast flank of the Illinois basin. The field, discovered in Oct., 1962, was converted to a gas storage field on Jan. 1, 1970. It has the potential of being one of the largest gas storage reservoirs in the country and is ideally situated for effective market requirements. The field is approximately 10 miles long and 1-1/2 miles wide, and originally contained 123.6 Bcf of native gas. At the time it was converted to gas storage, 72 Bcf had been produced. The balance was retained for a storage cushion volume.

The Midland gas field produces from the Bethel sandstone of the Lower Chester section of Mississippian age. The rather narrow and elongate physical attitude of the reservoir is the result of a sand fill in a channel cut into the underlying Mississippian carbonates. The maximum thickness of the Bethel Channel fill is in the order of 250 feet.

Diligent collection of reliable basic log and core data, together with the accumulation of an accurate pressure and production history during the productive life of the field is quite important. Because of early planning and persistence, this information has been collected persistence, this information has been collected for very little additional cost. A comparison based on such data is made between original gas-in-place calculations using volumetric methods, steady-state material balance and unsteady-state material balance. This data can also be utilized in additional programs which are needed for future underground storage operations.

Introduction

Midland gas field is located in Muhlenberg County, Ky. along the southeast flank of the Illinois basin. As shown in Fig. 1, it is located in an area marked by numerous gas and oil producing fields. The discovery well, drilled in Oct., 1962 encountered gas in the Bethel Channel sand of Mississippian age at a depth of approximately 2,100 feet.
An Electromagnetic Method of Orienting a Gun Perforator in Multiple Tubingless Completions
Authors: Stroud S.G. , DeGough K.G.
Published: December 2007

In multiple tubingless completions, two or more strings of casing are run and cemented in the same borehole.

In order to perforate one string and avoid damaging adjacent strings, it is necessary to orient the perforating gun away from adjacent strings. Orienting systems which have been used include the mechanical method, the radioactive multiple line method, and the radioactive single line or density method.

The electromagnetic orienting tool is a new approach to the problem of orienting a gun perforator. It operates by detecting adjacent strings based on their magnetic properties. This method is not affected by properties. This method is not affected by cement or formation density since it responds only to magnetic material. No radioactive sources or radiation detectors are used.

This tool has been field-tested for several months with good results and a high degree of reliability. Having a diameter of 1-11/16" O.D., the tool will pass through 2-3/8" O.D. tubing and successfully orient in 4-1/2" O.D. casing.

Introduction

A method of completing a well with multiple zones consists of running two or more strings of casing in a side by side relationship, into a well bore which penetrates all the zones. In normal practice penetrates all the zones. In normal practice all strings are run to about the same depth. In order to produce a particular zone, a gun perforator is run into one of the strings of perforator is run into one of the strings of casing and placed opposite the zone to be produced. The gun must be of the type which produced. The gun must be of the type which fires in a single direction and must be directed so that other casing strings will not be perforated. In this manner each zone may be produced independently from a different casing string.

In order to perforate one string and avoid damaging adjacent strings, it is necessary to orient the perforating gun away from the adjacent strings. Orienting systems which have been used include the mechanical method, the radioactive source method using multiple lines, and the radioactive single line or density method.

The mechanical method has become obsolete because of inflexibility and high cost. The multiple line radioactive method accurately locates adjacent strings but has the disadvantage that all strings must be entered with wire lines.
Coarse Grind Cement for Oil Well Cementing
Authors: Clark Charles R. , Steele John H. , Gidley John L.
Published: December 2007

This paper describes the performance properties of a retarded Class H properties of a retarded Class H cement that was developed by removing the fines from the cement powder. Such a cement should be useful for high-temperature cementing because of its increased thickening time. Slurries prepared from the coarse grind cement powder provide high compressive strength, low permeability of the set cement, and acceptable free water content.

Introduction

Development of a slow set cement by using a coarsely ground cement powder is not new. Knowledgeable powder is not new. Knowledgeable people in the cement industry have people in the cement industry have long recognized that large particles of cement, having smaller surface area and being less reactive, should provide longer thickening time. provide longer thickening time. Coleman and Corrigan studied the effect of cement fineness on the ratio of set cement volume to slurry volume and the permeability of set cement. However, permeability of set cement. However, to our knowledge, data pertaining to the effect of particle size on thickening time and. other cement performance properties has not previously been properties has not previously been published. Therefore, the objective published. Therefore, the objective of this paper is to determine the magnitude of this effect and to determine whether sufficient retardation could be achieved to be of practical value for deep well cementing.
Energy from Oil Shale: Environmental Research
Authors: Cook Glenn L.
Published: December 2007

The development of the vast energy resources of the oil shales of the Green River Formation in Colorado, Utah, and Wyoming requires the application of satisfactory environmental controls. Expected waste materials from processing oil shale are the shales from processing oil shale are the shales from which the organic materials have been removed, waters produced during retorting or mining, and gases produced during retorting. Present status of environmental research on oil shales at the Laramie Energy Research Center will be discussed.

Introduction

Environmental research associated with the future production of energy from oil shale is directed toward the identification of possible problems and the solution of those possible problems and the solution of those problems before any large-scale use is made problems before any large-scale use is made of the shale. In the words of Bureau of Mines Director Osborn, speaking at commencement exercises at the New Mexico Institute of Mining and Technology in May of this year, "… the truth is beginning to dawn: Most of American's environmental problems are related, in one way or another, to the production and use of minerals and fuels." production and use of minerals and fuels." The presently small, but growing, environmental research effort on oil shale has the mission of preventing environmental degradation when an oil-shale industry comes into being.

Concern for the protection of the environment has resulted in several studies. The States of Colorado, Utah, and Wyoming have each prepared reports on the environmental problems peculiar to their states. problems peculiar to their states. The Oil Shale Corporation (TOSCO) has an active research program investigating possibilities for revegetating retorted possibilities for revegetating retorted shale. Denver Research Institute and The Colorado State University have each studied some of the problems of disposal of retorted shale. The neighborhood effects, those that affect people and land areas adjacent to proposed operations, are being studied by the Bureau of Land Management. One study of such effects was made at the Utah State University at Logan, Utah. The latest proposal for the use of nuclear explosives in a recovery scheme for oil from shale, called Project Utah, will include environmental plans in the Project Definition.
Desalination of Brackish Waters by Ion Exchange
Authors: Epstein A.C. , Yeligar M.B.
Published: December 2007

Recent developments in ion exchange technology have made it economically feasible to desalt blackish waters. Four ion exchange systems capable of desalting brackish waters containing 1000 to 3000 ppm of TDS are reviewed with respect to their technology, operating results and operating costs. Laboratory and field studies of these systems show that desalination of brackish water is technically feasible and that the most economical systems depend on the characteristics of the brackish water, the characteristics of the desalted water and the required quality of the product water (desalted water blended with brackish water) for its end use.

Introduction

The petroleum industry is second, only to the steel industry, as a consumer of water. The water, whose acceptable quality varies from poor to excellent, is needed both at refineries and in the field. Many of these sites are located where the only major source of water is brackish.

Demineralization by ion exchange of waters containing less than 500 ppm has been an accepted practice for many years. For this type of water, the chemical cost, capital cost, labor cost and maintenance cost compare favorably with other systems, such as reverse osmosis, distillation, etc. In addition, ion exchange processes are usually easier to build, simpler to operate and produce water qualities as good as those obtained from other systems.

Ion exchange demineralization of waters containing greater than 500 ppm TDS has been infrequent. As the salinity increases, the capital cost and operating costs increase. This is because large volumes of ion exchange resins are necessary and high consumptions of regenerants are required.
Application Of A Computer Information System To Surveillance And Analysis Of Production Behavior In Complex Fields
Authors: Cronquist Chapman , Hodgson Robert
Published: December 2007

Many oil and gas fields are characterized by extensive faulting and multiple pay zones with lateral facies variation. These fields contain many apparently separate pay-zone segments. Often, however, groups of pay-zone segments. Often, however, groups of these apparently separate segments are in communication and form common reservoirs. Geologic and engineering interpretation in this type of field are subject to continuous revision as new data are received.

Optimal exploitation under these conditions requires early recognition of communication between pay segments, resolution of possible inconsistencies between geologic interpretation and observed production behavior, and determination of reservoir drive mechanism. Continuing analysis is required to indicate areas where new wells should be drilled, zones where existing wells should be recompleted, and reservoirs where fluid injection is needed to increase recovery efficiency. This requires continuous surveillance of large amounts of production and well test information. Resolution production and well test information. Resolution of geologic-production inconsistencies often is a trial and error process which may require interpretive investigation of combinations of pay segments involving many individual well performance histories. Under these conditions, performance histories. Under these conditions, surveillance and analysis using manual techniques is time consuming and expensive. The problem is more one of data management than of geologic interpretation or reservoir analysis.

This kind of problem may be solved economically by using a comprehensive machine data management, retrieval, analysis, and report generating system. This paper describes one such system, called COMPS, which enables the construction and maintenance of large files of production and geologic information and allows selective retrieval, aggregation and reclassification of any desired combination of information about wells or pay segments. COMPS is user-oriented and pay segments. COMPS is user-oriented and does not require prior knowledge of computer programming. All capabilities of the system programming. All capabilities of the system are called upon by the engineer or manager through a set of easily understood commands which utilize terminology, codes, and identifiers suitable to the problem at hand.
The Hot-Film Flow Log--A Formation Evaluation Tool Designed for Shallow In-Situ Oil Shale Experiments
Authors: Thomas Harold E.
Published: December 2007

The Hot-Film Flow Log was developed for evaluating shallow in situ fracturing and retorting (combustion) experiments in Green River oil shale. Two logging probes are described which employ a temperature-compensated conical hot-film anemometer-type flow sensor. Wellbore fluid flow profiles and fluid entry or exit points can be recorded while continuously lowering or raising the probes in cased or uncased wellbores.

Natural, hydraulic, and explosive fractures in oil shale have been evaluated by a combination of air injection, air production, and flow logging techniques. Fracture depths, types (horizontal or vertical), and flow characteristics within a single borehole or a system of boreholes can be interpreted from the logs. Gas flow profiles in in-situ retorting experiments can be determined before ignition, during formation combustion, and after combustion termination.

Limitations and potential applications are discussed.

Introduction

The U.S. Bureau of Mines is presently conducting field experiments near Rock Springs, Wyo., to determine the feasibility of in situ or underground retorting of Green River Formation oil shale at depths of 75 to 450 feet. Most oil shale is an impermeable rock and does not contain oil; however, it contains a solid carbonaceous material known as kerogen which converts to a crude-oil like liquid when heated to 700 degrees to 900 degrees F. To be retorted in situ through a system of wells similar to those in an oil or gas reservoir, oil shale must first be fractured by some means to provide flow paths between wells for injected and produced fluids.
The RamRig Concept For Drilling and Workover Rigs
Authors: Vatne P. A. , Norheim Pal
Published: December 2007

The introduction of the RamRig concept signifies, by its radical new design, a number of substantial savings to both the construction and operation of drilling and workover rigs for the petroleum industry. The RamRig can be used for floating and fixed installations and eliminates the need for large derrick with drawworks, drillstring compensator etc. This novel concept can be used as a small workover to full scale drilling rig and opens perspectives for new ways of drilling wells and for improved economy in future offshore field developments.
Case Study - Building a System in a Service Company To Assure Technical Integrity and Institutionalize Organizational Learning
Authors: Rixse M.R. , Thorogood J.L.
Published: December 2007

SPE and IADC Members

A service company and operator worked together to build a system to assure technical integrity within the service company's field operating location. They created systems and procedures to address how the service company is organized, how it performs design, how it executes the service, and how it manages the logistical issues associated with performing the service. Additionally the procedures were structured to facilitate gathering and applying new knowledge.

The process was initially tackled from an ISO 9000 quality management standpoint, but the result lacked utility and was rejected. A more direct and universal approach was adopted that emphasized the safety-critical and cost-critical processes that are paramount requirements of an oilwell service operation.

Development of these systems was not a trivial task. Not only did it require extensive thought to define the exact scope of the issues which needed to be addressed, but the system had to be structured so that it would be actively utilized and not become a bureaucratic burden. Significant organizational culture changes were required to encourage personnel to learn and operate within the defined procedures. Using commonly available computer software, actively used systems are being implemented which provide access to the policies and procedures of both the operator and service company. The computer software also furnishes a simple framework to promote organizational learning.

Introduction

Directional drilling contractors are increasingly asked to take more responsibility by operators for well planning design and rig site operations. This occurs primarily because operators are continually looking for ways to improve their well construction performance. When contractors assume more responsibility, operator personnel are allowed to spend their time on value-creation activities rather than on quality assurance activities.

Before an operator considers streamlining his operations he may want to consider two issues associated with the transfer of responsibility:–contractor technical integrity to preserve the operator's "License to Operate"–contractor systems for the ongoing transfer and utilization of new relevant project information

Directional drilling contractors are very knowledgeable about the processes associated with directional drilling because of their extensive experiences specific to this part of well construction. They generally add significant technical value to a drilling project. But the fact that a directional drilling contractor has significant knowledge and a successful history of drilling directional wells does not necessarily prove that he operates in a technically rigorous manner. An operator may benefit if a contractor can assure that his design and Operations are technically sound.

Without open sharing of related project information, little significant value is gained by the operator when transferring additional responsibility to the contractor.

P. 241
Case History: Breitbrunn – Horizontal Foam Drilling Project in an Environmentally Sensitive Area in Bavaria, Germany
Authors: Hanking T. , Rappuhn T. F.
Published: December 2007

A depleted gas reservoir was converted into an underground gas storage in the sensitive Chiemsee lakeshore area east of Munich, Germany. Throughout the project considerable attention had to be given to environmental precautions and noise control. The project involved drilling five horizontal wells to a vertical depth of 1,950 m, with a horizontal displacement through a low-pressure reservoir of about 1,500 m. For the horizontal sections, stable foam was used to ensure safe drilling conditions and prevent formation damage. The foam system was employed for the first time in such horizontal drilling project in Europe. LWD systems for use with foam were not available. In the horizontal sections, paleontological and lithological methods were employed for steering through the narrowe sandstone reservoir. This technology was first tested successfully in a pilot well and then applied to the other four wells. The limited availability of disposal sites and high associated costs made it necessary to minimize the amount of contaminated fluids and cuttings. The liquid phase of the foam was therefore recirculated.