bluuebunny/crossref_metadata_2025 huggingface dataset:
A Compartmented Simulation System for Gas Reservoir Evaluation With Application to Fluvial Deposits in the Frio Formation, South Texas
Authors: Lord M. E. , Collins R. E. , Kocberber Sait
Published: December 2007

We present comparisons of simulations of performance histories for wells in highly compartmented, fluvial gas reservoirs generated by very precise finite element models and a much simpler multi-compartment material balance model. These comparisons validate the capability of this simple compartment model for the evaluation of compartmented reservoirs. Specifically we show that history matching of well performance with this simple model provides excellent estimates for directly drained pore volumes, supporting secondary pore volumes and intercompartment transmissibilities.
Drillable Selective Injection Equipment
Authors: Barneck M. R. , Petersen D. G.
Published: December 2007

Traditionally, selective injection equipment (SIE) has been manufactured from different kinds of metal alloys. SIE equipment, such as packers, sidepocket mandrels, and seating nipples, has been costly but the cost of retrieving or removing old equipment has been even more expensive.

Recently, drillable selective injection equipment has been developed for trial use in the Rangely Weber Sand Unit in Rangely, Colorado. The installations have been manufactured almost entirely of filament wound fiberglass and are almost metal free. Fiberglass cup-type packers have been developed and manufactured. Sidepocket

mandrels have also been developed and manufactured with a stainless steel pocket and the rest of the mandrel being made of fiberglass.

The only metal in the fiberglass or drillable part of the installations is some wire reinforcement in the rubber elements of the packers and the pockets in the sidepocket mandrels which are made of stainless steel (19" long each).

This concept will result in substantial savings in fishing operations when the installations need to be replaced. The top metal packers will be retrieved in the conventional manner. If the rest of the installations cannot be pulled out of the well easily, they can be drilled into small pieces with the small amount of metal either being retrieved in some kind of catch or driven to bottom. This will reduce workover rig time from weeks or even months to days.

Improvements in the next generation of drillable SIE are being pursued in an effort to address some specific concerns with the initial installation, such as packer wear going in the well, and drillable problems caused by the few metal parts. Fiberglass inflatable packers are also being developed to offer a choice in packer types available.
Removing a Typical Iron Sulfide Scale: The Scientific Approach
Authors: Ford W. G. F. , Walker M. L. , Halterman M. P. , Parker D. L , Brawley D. G. , Fulton R. G.
Published: December 2007

Iron sulfide scales vary in composition; this paper, in three parts, describes how a thorough analysis of the scale is necessary to optimize the chemical treatment and successfully remove the damage.

The first part of this paper describes the different types and compositions of iron sulfide scale and the need for a tubing cleanout prior to an acidizing treatment. The second part describes the detailed analysis of the scale through the use of quantitative X-ray diffraction analysis and elemental analysis by energy dispersive X-ray. The final part of this paper presents scale removal treatment case histories.
A Selective Water Control Process
Authors: Dalrymple E. D. , Dahl J. A. , East L. E. , McKown K. W.
Published: December 2007

A selective water control process that can control water production has been developed. This process incorporates small particle size cement (SPSC) in an oil-based slurry containing a surfactant. The system allows high concentrations of SPSC in the oil and retards the SPSC reaction with water to allow deep penetration into high permeability microchannels and fractures to shut off water. The slurry will set only if it contacts mobile water and therefore provides an excellent water control treatment.

The selective water control process has been used in conjunction with polymers crosslinked by metal crosslinkers to obtain reduction of water without the problems associated with crosslinked polymer, i.e., polymer production with accompanying corrosion and bacteria problems. This paper demonstrates the application of the selective water control process in various types of formations, ranging from sandstone to fractured limestone, dolomite, and chert. Field case histories of the process are presented for perforated and openhole completions.
Benefits of Performing an Acoustical/Mechanical Study on a Four-Unit Compression Installation
Authors: Vevurka J. W. , Fifer Frank
Published: December 2007

Every reciprocating compressor transmits pulsations into the piping system. These pulsations may or may not result in problems such as high vibrations, poor performance, or measurement error. Given that pulsations are inherent in reciprocating compressor installations there are basically two approaches from a pulsation/vibration point of view to installing a reciprocating compressor package: Design and build the package with very little conscience consideration given to potential pulsation and vibration problems. At start-up try to fix any problems that occur.Have an acoustical/mechanical study performed and implement the necessary modifications prior to fabricating the package.

This paper discusses the benefits of performing an acoustical/mechanical study on a reciprocating compressor installation. Recently such a study was completed between Arkansas Western Gas Company (Owner), PAMCO (Equipment packager) and Beta Machinery Analysis Ltd. (Engineering company who performed the study). Predicted As Found versus Final Modification pulsations and unbalanced forces are presented.

Pulsation control, whether it be via a simple volume bottle or a bottle designed with internals, is required for most reciprocating compressor installations. There are capital and operating costs associated with these pulsation control devises. Performing an acoustical analysis enables these devices to be designed to optimize the pulsation control, capital cost and operating cost (pressure drop) over the range of operating conditions expected during the life of the compressor. Excessive pulsations can directly effect compressor performance and indirectly have an adverse effect on the piping system. Some of the concerns, all of which have associated cost, are: Lower volumetric efficiency leading to decrease in capacity.Higher valve losses resulting in increased brake horse-power/MMSCFD.Pulsation induced valve vibration leading to possible failures.Increased rod loading sufficient to cause rod failures.Pulsation induced cyclic rod loading transmitted to the compressor crankshaft as dynamic torque and excited torsional shaft vibrations, which may lead to possible failure.Acoustical response coincident with torque mechanical natural frequency, which may cause rod failure and possible crankshaft failure.

Uncontrolled pulsation will, in the long run, cost money. This will be spent in the repair of worn and failed parts or downtime (lost revenue) and increased fuel consumption of the compressor unit.
Viscous Property Measurement of Delayed Titanate Crosslinked Gels Containing Oxidative Breakers
Authors: Craig D. P. , Fan Yong , Holditch S. A.
Published: December 2007

Since 1983, the Gas Research Institute (GRI) has funded research to improve the knowledge and understanding of the viscous properties of fracturing fluids. One of the GRI research projects was the development and testing of the GRI Rheology Unit, which is a mobile rheology laboratory that can be taken to the field to measure the viscous properties of the actual fluids being pumped during the treatment.1–2

The GRI Rheology Unit consists of a van containing two Fann Model 50 viscometers and a complete wet chemistry laboratory. In typical field operations before the treatment begins, the Rheology Unit is used to check the fracturing fluids for contaminants and to verify the fracturing fluid, mixed with the chemicals to be used during the treatment, meet the design specifications. During the treatment, the Rheology Unit is used to sample and test the fluids being pumped to ensure fracture fluid quality.

Field research with the GRI Rheology Unit has found that laboratory measured fracturing fluid properties are often not reproduced under field conditions.1–2 During the majority of treatments monitored with the GRI Rheology Unit, fluid problems were diagnosed by testing the gel using the Fann Model 50 viscometers. One of the most common fluid problems experienced in field operations is the scheduling and addition of the chemical breakers used to degrade the fracturing fluid after the treatment. Typical problems associated with the breakers were either (1) the wrong breaker type was being used or (2) the wrong amount of breaker was added for the given conditions.
Fracture Identification from Well Logs
Authors: Iverson W. P.
Published: December 2007

The Silo oil field in southeastern Wyoming produces oil from the fractured Niobrara chalk. Chalk has very little matrix permeability and produces best from areas where, the chalk contains pervasive open fractures. This fractured reservoir is examined with five physically independent fracture characterization techniques; oriented micro-resistivity logs, borehole elongations, sonic logs, nuclear logs, and vertical seismic profiles. In this reservoir, at this location, the oriented micro-resistivity logs give the best overall identification of fractured intervals, probably because the most productive fractures are open and fluid filled. Borehole elongations, commonly called breakouts, also correlate with fractured intervals. Fractures are found both parallel and perpendicular to borehole breakouts. Sonic waveform attenuation also correlates with fractured intervals, although no orientation information is provided by the sonic log or the other nuclear porosity logs. The M-N nuclear-sonic logging technique is shown to work only for one well in this area, yet the response is due entirely to density log anomalies. A second M-N plot from Silo shows no indication of fractures while the well produced oil from fractured chalk. The final fracture identification technique shown in this paper is the vertical seismic profile. Shear waves are polarized into fast and slow directions due to anisotropy of the fractured chalk.
Well Performance Evidence for Compartimented Geometry of Oil and Gas Reservoirs
Authors: Junkin J. E. , Sippel M. A. , Collins R. E. , Lord M. E.
Published: December 2007

Well pressure and production histories and transient pressure tests, evaluated by conventional well testing techniques and simulation, are shown to indicate compartmented reservoir geometry arising by depositional and diagenetic processes. Examples are cited of both clastic and carbonate reservoirs but the central focus of this study is on fluvial deposits exhibiting stratigraphic compartmentation. Field examples of compartmented behavior in such reservoirs are demonstrated by wells with spacing corresponding to separations as small as 1/4 mile. Furthermore, directly drained compartments with radii as small as 60 feet are demonstrated. The impact of such compartmentation on development strategies is examined.
Application of Matchstick Geometry To Stress Dependent Permeability in Coals
Authors: Seidle J. P. , Jeansonne M. W. , Erickson D. J.
Published: December 2007

Several investigators have reported coal permeability decreases with increasing stress, but no conceptual model has been advanced to explain this effect. To better understand the permeability of stressed coal, a theoretical and experimental program was undertaken. A common naturally fractured reservoir geometry, a collection of matchsticks, was extended to stressed coalbeds and tested against laboratory measurements using samples from the San Juan and Warrior Basins. Good agreement was obtained between theoretical behavior and laboratory data. Equations are presented for converting laboratory measured stress-permeability data to (a) in-situ permeability as a function of depth of burial in a basin, and (b) to reservoir permeability during coalbed depletion.

Coal cleat compressibility, analogous to pore volume compressibility of conventional reservoirs, has historically been difficult and expensive to measure and the results of such measurements are often ambiguous. A method is presented for calculating cleat volume compressibility from stress permeability experiments, resulting in considerable savings of both time and money. Stress-permeability and cleat volume compressibility results reported here are compared with those published in the literature.

Evidence in the literature indicates that coal matrix shrinks when gas is desorbed, increasing cleat permeability. Assuming a matchstick geometry and using a coal matrix shrinkage coefficient reported in the literature, the increase in cleat permeability due to matrix shrinkage was calculated. The increase in permeability due to matrix shrinkage during depletion is compared with the decrease in permeability due to increased stress.
Microfracture Stress Tests, Anelastic Strain Recovery, and Differential Strain Analysis Assist in Bakken Shale Horizontal Drilling Program
Authors: Kuhlman R. D. , Perez J. I. , Claiborne E. B.
Published: December 2007

The economical completion of the Bakken Shale often dictates the drilling of a horizontal wellbore. A horizontal wellbore placed through a naturally fractured shale formation introduces drilling problems of wellbore collapse, the opening of existing natural fractures, or creation of fractures. Knowledge of magnitude and direction of the in-situ stresses is important in determining the optimum direction to drill a horizontal wellbore. The stress direction is important because a horizontal wellbore has its maximum stability when it is in the direction of minimum principal in-sttu stress. Combining the in-sttu stress magnitude data from microfracture stress tests, the in-sttu stress direction from anelastic strain recovery and differential strain analysis, and mechanical properties from laboratory tests, one can determine the minimum and maximum allowable drilling mud weights and optimize wellbore direction if necessary.1

The microfracture stress test was used to determine stress magnitude. Successfully performing the microfracture tests has meant overcoming problems inherent in performing these tests at high temperatures and high injection pressures associated with deeper wells in addition to concerns with the naturally fractured shale's stability. Some special equipment was required for the tests. Special surface injection equipment, developed in recent years was used to perform the tests. Standard downhole drillstem testing tools were deemed to be the most appropriate and were used in a special configuration to isolate the zones of interest and to overcome some of the problems associated with temperature and pressure (increasing depth), the natural fractures, and problems with borehole sloughing.

Problems peculiar to naturally fractured shale affected the anelastic strain recovery (ASR) and differential strain analysis (DSA) testing.

This paper presents a systematic approach for determining in-sttu stress field direction and magnitude and applying these measurements to determining the minimum and maximum limits of mud weight and wellbore direction for optimum drilling design in the Bakken Shale.
Constant Curvature Method for Planning a 3-D Directional Well
Authors: Guo Boyun , Miska Stefan , Lee R. L.
Published: December 2007

A new method for planning 3-D directional wellpaths is proposed in this paper. This method, which is referred to as the Constant-Curvature Method, has several advantages over the conventional Radius-of-Curvature Method and Constant-Turn-Rate Method. The new method yields constant curvature wellpath sections which are compatible with the directional performance of deflection tools. In addition to this advantage, this method also yields less dogleg severity of well trajectories, and, consequently, less drag and torque on the drill string. As a result, it is expected that the directional drilling operation should be easier, safer, and more economical if the wellpaths are planned using the proposed method. Mathematically, the formulation of the method involves integrals that do not have closed form solutions and need to be estimated numerically. To avoid the numerical integrations, two alternative approximations to the exact solution, namely Piecewise-Radius-of-Curvature Method and Piecewise-Constant-Turn-Rate Method, are presented. Sample computations show that the Piecewise-Constant-Turn-Rate Method gives better approximations and the calculations can be carried out using a hand-held calculator.
The Use Of Fluid-Loss Additives In Hydraulic Fracturing Of Oil And Gas Wells
Authors: Hawsey Jerry D. , Jacocks Claude L.
Published: December 2007

The theory of low fluid-loss hydraulic fracturing as a means of stimulation to oil and gas wells is presented. The fluid-loss properties of current fracturing fluids are shown by a demonstration of the API testing method. Fluid-loss test results are interpreted in comparing fracturing fluids.

Introduction

The method of fracturing to be discussed is not new. It is a process introduced to the oil industry in 1955 and was used sparingly at the outset, but has experienced tremendous growth in the past three years.

The discussion will be divided into three parts. 1. Presentation of the theory of low fluid-loss fracturing. 2. Demonstration of the fluid-loss properties of current fracturing fluids. 3. Interpretation of fluid-loss test results in comparing fracturing fluids.

HISTORY OF FRACTURING FLUIDS

First, a brief discussion of the history of fracturing fluids. Fracturing began in 1949 with the initial fracturing fluids consisting of viscous fuel oils, gelled kerosene or napalm. During the next five years, little change took place in the nature of fracturing fluids. The first major change occurred in 1954 with the advent of low fluid-loss additives. Prior to this time, it was believed that viscosity was necessary to prevent sand outs; however, this was soon disproved by the use of fluid-loss additives in lease crude. Fracturing methods changed tremendously during the years following 1954, and in 1957 Howard and Fast presented a paper covering the mathematical treatment of the factors controlling fracture extension. Present-day fracture calculations are based largely on this work. Today, with economical and efficient fracturing fluids, many jobs utilizing an excess of 100,000 gal of fracturing fluids are being performed. In fact, a major oil company in 1959 fractured a well in South Texas in one stage using 180,000 gal of lease crude and put away 270,000 lb of sand with the aid of a low fluid-loss additive. The use of low fluid-loss additives has more than quadrupled in the last six years, and in 1960 over 125 million gal of fluid with low fluid-loss additives were pumped.

THEORY OF LOB FLUID-LOSS FRACTURING

First, the mechanics of fracture extension as illustrated in Fig. 1 should be investigated. The left portion of this figure shows the result of using high fluid-loss fracturing fluids.
Nimr Medium Radius Horizontal Learning Curve
Authors: Perry B. D. , Ali I. H. , Vancura J.
Published: December 2007

In January 1991, Petroleum Development Oman L.L.C. began a campaign to drill six medium radius horizontal wells in the Nimr field in South Oman. The wells were drilled with a 12-1/4" build up section followed by an 8-1/2" horizontal section. On the basis of this campaign, a decision was made to extend the number of horizontal wells to be drilled in the Nimr field during 1991. The first three wells of the second campaign were drilled to the same design as the original six wells, principally due to the non availability of certain tubulars needed for a radical design change. Once the required equipment was available, the wells were drilled and completed with a Composite Liner Design, i.e. the build up and horizontal sections were drilled and cased in the same hole size.

This paper discusses the original well design criteria, the results of the operational learning curve (the new design concept for Nimr wells), and the economic benefits. By the end of February 1992, four of the new design wells had been successfully drilled and completed.
Vibration Of Oil Well Cement
Authors: Skalle P. , Sveen J. , Justnes H.
Published: December 2007

Gas leakage through cement in the annular space around a cemented casing is still a serious problem, although new additives and methods have reduced the problem. The problem is related to migration through the cement matrix itself or to migration along the cement's Interfaces with the casing and the formation, caused by poor displacement of mud and/or loss of hydrostatic pressure within the cement slurry during curing.

One solution to this problem Is to transmit vibrations to the cement through the casing. The objective of vibration of oil well cement is to counteract the continuous reduction of hydrostatic pressure and to maintain low permeability during hydration of cement. The hydrostatic pressure within the slurry must be higher than the pressure within the gas bearing formation. Vibration tests in a two meter high cement column have resulted in guide lines as to what frequency, amplitude, vibration Intervals and duration should be selected to maintain column pressure. For similar vibration parameters it has also been investigated if the short (1 day) and long term (7 days) strength of the cement has been negatively influenced. Different methods for practical implementation of oil well vibrations have also been considered.

Through vibration of oil well cement, not only the cement will become more gas tight, but also the physical bond between cement/casing and the strength of the cement itself will be considerably improved.
An Integrated Approach To The Recognition and Characterisation Of A Fractured Limestone Reservoir In The Ilam Formation, Fateh Field, Dubai – U.A.E.
Authors: Wood J. R. , East G. R.
Published: December 2007

Reservoir Engineering and Geological data gathered from 22 years of production from the Fateh Ilam reservoir and from almost 200 wells cannot be reconciled using existing reservoir and geological models. Prior to building a full field model to evaluate further development of the waterflood and potential for future infill drilling, a better understanding of the reservoir is required.

Recent re-characterisation of the reservoir is described and results are summarized from a fully integrated reservoir study that showed the Ilam to be both complex and heterogeneous. Examination of the core and log data revealed orientable fractures that, following detailed analysis, were seen to be crudely related to lithology. The study also shows that the wide range of pressure transient characteristics and anomalous production and waterflood behavior observed in the Ilam can be explained using a simplified model consistent with these findings.
Geochemical Study of Crude Oils and Source Rocks in Onshore Abu Dhabi
Authors: Lijmbach G. W. M. , Toxopeus J. M. A. Buiskool , Rodenburg T. , Hermans L. J. P. C. M.
Published: December 2007

The Petroleum geochemistry of Abu Dhabi onshore has been studied. From cutting and core analyses the presence of five main source rock intervals could be established in the Middle Cretaceous Shilaif Formation, the Lower Cretaceous Shuaiba Formation and Bab Member, the Upper Jurassic Dukhan Formation, the Upper Triassic Minjur Formation and the Permian Khuft Formation. Analyses of 13 crude oils resulted into five oil families. The Simsima reservoired oil of the Shah field appeared to originate from the Shilaif Formation source rock, while the Shuaiba oil of the Shah field is sourced from a shaly Bab Member source rock. The Kharaib reservoired oils in the Asab, Bu Hasa, Rumaitha, Sahil and Jam Yaphour fields originate most probably Irom Bab Member source rocks, while the Qatar and Habshan reservoired oils of the Bu Hasa and Shah field are likely to be related to Dukhan source rocks. For the Habshan oils of the Shah field, investigated in this study no matching source rock could be identified yet. Finally a maturity modelling study for the main source rock bearing Stratigraphie intervals was carried out.
Multi-Well Data-Base: An Example Of Field Applications
Authors: El Hadidi S. , Dajani F. , Reiss A. , Plomb J-P.
Published: December 2007

Data-bases have become a topical subject in the oil industry. In the absence of any previous experience in this domain by oil field personnel, the tendency is either, to try and invent the wheel, or to borrow ideas from other industries with database experience. Either of these courses could be very expensive and could lead to a cul-de-sac.

The ADNOC Data-base in Abu Dhabi is probably the most advanced petrophysical multi-well database (MWDB) in the oil business. After five years of dedicated data-base work by a team of specialists, with all the data of approximately 2200 wells that represents over 7 million feet of open hole loaded, a wealth of experience and expertize was developed to write professionally on the subject of data-base applications in the oil industry.

This paper presents a case study of a data-base application for a large field. The paper discusses the organization and input of all types of well and field data, data quality control, normalization of all the data for field consistency and homogeneity, and the field and multi-well concept of data interpretation and estimation of missing data. The paper discusses in detail the applications of the data-base for reservoir simulation and for Stratigraphie and structural studies of the various formations and layers in a field. The emphasis here is that a data-base is not just an instrument of data storage and retrieval, but is an effective way to manage the reservoir.

One of the main conclusions made was that an effective data-base can be used to efficiently utilize human resources so that an engineer can spend 10% of his time sorting and searching for data and the remaining 90% doing effective analysis. In the absence of an effective data-base, the tendency is reversed; 90% sorting and searching and 10% of analytical work.
Brine Deterioration Of Cement And A Replacement Cementing Technique
Authors: LaFleur K.K. , Lovelace W.P.
Published: December 2007

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

Field studies of wells on the Nesson Anticline in North Dakota have shown that cement placed during original primary cementing operations in many of the wells has now deteriorated to the point that zone isolation no longer exists. In their present condition, they cannot be stimulated or used successfully as injection wells. Squeeze cementing has proved highly uneconomical because many repeated stages are required. Even with repeated stages, success ratios have been extremely low. This paper describes a replacement cementing-technique developed to remove deteriorated cement and replace it with new cement. While developed for Nesson Anticline wells, the technique should prove successful in other areas where similar problems exist. problems exist

Introduction

Many of the wells producing front the Madison formation along the Nesson Anticline in North Dakota had declined as early as 1963 to a point where they would no longer produce their allowable. Some stimulation was started at that time. In 1966, however, North Dakota allowables were raised, and a great number of the wells were treated with large volumes of acid to increase the production. The majority of these wells treated on vacuum. Little or no increase in oil production resulted from the treatment, although there was often a large increase in water production. Wells which required surface pressure to displace the acid showed good increases in oil production.

It was suspected that channels existed in the primary cement in the wells which treated on vacuum and that the acid was not entering the desired producing zone. The wells which treated with pressure were believed to have the primary cement intact. Acid was confined to the desired zone and reservoir penetration with the acid provided good production increases.
An Overview Of 1991 Oil Spill In The Arabian Gulf And Fires In Kuwaiti Oil Fields
Authors: Alam Ibrahim A. H.
Published: December 2007

The Gulf war oil spill and the fires of the Kuwaiti oil fields are probably the worst two environmental crisis in human history. At the end of January 1990, intentionally spilled oil was reported in Kuwaiti and Northern Saudi Arabian waters. The magnitude of the spill was unknown and estimates varies from 0-5 to 11 million barrels (best estimate according to Meteorology and Environmental Protection Administration (MEPA) is 4-6 million barrels). It is the greatest oil spill ever to occur in human history. The time and location during the Gulf war and in war zone have added further burdens on this environmental catastrophe and opened a new chapter of environmental war crimes in human history.

The Research Institute of the King Fahd University of Petroleum and Minerals (KI/KFUPM) was assigned to be the scientific focal point during the crisis. Oil spill experts and scientists joined the Emergency Response Center to offer their expertise and enhance their knowledge. The available resources in terms of library, books, research of the area, equipment and human resources at all levels were optimally utilized.

International environmentalist team along with local scientists were organized to review the available literature and participate in field survey, aeroplane surveillance, planning future action and evaluation of suggested techniques and solutions. Scientific meetings were held on regular basis to review day to day status and exchange information and follow up on development
Drilling Fluids: Making Peace With the Environment
Authors: Bleier Roger , Leuterman A. J. J. , Stark C. L.
Published: December 2007

Environmental problems, although nettfesome and often costly, have served to stimulate new developments in drilling fluid technologies. Minimizing environmental impact involves reducing levels of toxic components in drilling fluids, as well as waste minimization and recycling. Significant progress is being made. This paper assesses the current state of technology and the likely directions for the future. The constructive role of regulatory agencies in recognizing, fostering, and encouraging the use of emerging technologies, as opposed to blanket prohibitions, also is discussed.

Mud companies have identified replacements for diesel and mineral oils in lubricants and spotting fluids that combine performance and environmental acceptability. Non-chloride potassium sources have replaced KCI in many water-based muds. New cationic polymer muds are being touted as replacements for oil-based muds in many situations, and preliminary field results are encouraging.

The trend to polymer muds, in general, has reduced consumption of traditional lignosulfonate additives and other organo-metallic complexes. Weighting agents also have been affected. Barite ore sources are scrutinized carefully for their trace heavy metal content with particular attention to cadmium and mercury impurities.

Muds based on synthetically made, low-toxicity, biodegradable, organic liquids are now available. These synthetic-based muds offer "designed-in" performance and environmental characteristics.

Processing of drilling fluid waste is a rapidly growing industry. Technologies commercially available include dewatering, landfarming, cuttings injection, fixation, and distillation. Bioremediation and solvent extraction have promise for the future.

All of the above affect the economics as well as the environmental acceptability of drilling operations. Tradeoffs between environmentally desired features, e.g., lower toxicity but larger waste volumes, also are addressed.
Partnering in the 90's: A Case History
Authors: Divine R. O. , Lingafelter J. A.
Published: December 2007

This case history of a multi-well program in the Austin Chalk illustrates successful application of "partnering" between a major Operator and service company. The concept of partnering, as addressed in recent industry literature,(1,2,3,4) involves arranging the risk/reward structure of a contract to align the objectives of both Operator and service company. This may be achieved by instituting a performance incentive contract which ties service company compensation to performance, with attendant bonus compensation for performance which surpasses predetermined standards.

In this instance, the Operator and service company worked in conjunction and developed a drilling plan to efficiently achieve the Operator's geologic and economic objectives. The service company was contracted to provide multiple services under a single performance incentive contract. The Operator, multi-service supplier, and drilling contractor developed a teamwork apporach which ultimately improved the process of pre-planning, implementation and analysis that made the multi-well program an economic and technical success for all parties.
Drilling for Quality
Authors: Sandison G. F. , Kern A. M.
Published: December 2007

This paper discusses the successful application of the Quality Process in an operations environment. Historically, drilling and workover groups have operated in a very independent manner. Their relationships with customers were often difficult and sometimes adversarial. The introduction of the Quality Process has helped to change this at one major oil company.

The main elements of the paper are: A review of the Quality ProcessA case history concerning the Rig Operations Department of a major oil company
Application of Quality Standard ISO 9001 to Directional Well Planning
Authors: Johnstone J. A. , Fernandez R. L.
Published: December 2007

Adoption of a quality system is recognised as an important step towards improving service quality, increasing efficiency and ensuring safety issues are suitably addressed. In this respect, ISO 9001, which is an internationally accepted quality standard, is well equipped to address the steps inherent in the directional well planning process.

When an operator relies on a directional service company to provide essential well planning services, development of an optimum well path is dependent on the frequent exchange of information between the service company and participating groups within the operating company, for example Geology, Engineering and Drilling departments. In most cases, the well profile undergoes significant revision before the final well path is realised.

Implementation of a quality standard such as ISO 9001 provides a means to address accountability for, as well as documentation of, quality systems in place during the well planning process.

This paper describes an innovative application of an internationally recognised quality standard and focuses on the actual implementation of ISO 9001 to the process of directional well planning, detailing aspects such as document control, design review and verification procedures.
Reduction of Naturally Occurring Radioactive Material Disposal Volume by Chemical and Physical Treatment
Authors: Mason J. Y. , Block R. J. , Knippers M. L.
Published: December 2007

Naturally Occurring Radioactive Material (NORM) has been deposited in tanks, pipelines and pits of many oil fields in North America. Increasingly stringent environmental regulations and escalating disposal costs will make NORM a major environmental issue in the 1990s. Reduction of the volume of NORM for disposal has been accomplished through chemical treatment to separate hydrocarbon from solids, followed by physical segregation of the processed solids according to particle size and density. Laboratory and field studies show that the radioactive constituents of these produced solids reside within contained barite and calcite. Separation of the radioactive components from the sand, hydrocarbon, clays and silt produce a fourfold to fivefold reduction in NORM volume for disposal. The particle size of NORM solids can be further reduced to allow suspension and down hole disposal. This completely eliminates the need for off site disposal when suitable wells are available.
Disposal of Filter Media Used in Exploration and Production Operations
Authors: Morrissey Susan , Hashemi Reza
Published: December 2007

Cartridges filters and diatomaceous earth used in exploration and production operations are managed according to the nature of the fluids that they have been exposed to. The filtration industry has employed practices of source reduction and minimization to avoid waste generation whenever possible. The industry adheres to waste management guidelines in compliance with Federal, State and local regulations. This paper sets forth the criteria to determine if the used filter cartridges and diatomaceous earth are considered hazardous wastes under the Resource Conservation and Recovery Act and discusses approaches for disposal.
Ultrasonic Cement Evaluation in Inhomogeneous Cements
Authors: Gong Ming , Morriss S. L.
Published: December 2007

Although large sized heterogeneities in the cement sheath may indicate zonal isolation problems, not much work has been done to quantify their influence on ultrasonic pulse-echo cement evaluation measurements. For these measurements, "large" means having a characteristic dimension greater than the wavelength of the ultrasonic wave, which is on the order of a quarter of an inch (6.4 mm) in most cements. To determine the effect of large gas bubbles in cement on these measurements, experiments in 7 in. (178 mm) casing with a simulated tool and simulated bubbles have been performed. The results indicate that the shape of the heterogeneity is the most influential factor in the measurement. Most cement log pathologies, e.g. microannulus and tool eccentering, make the measurement pessimistic (the cement is as good or better than the log indicates). For spherical inclusions in the cement the opposite appears to be true: the measurement is optimistic, being only slightly influenced by the bubbles, even at high concentrations.
Drillstring Vibrations: A New Generation Mechanism and Control Strategies
Authors: Aldred W. D. , Sheppard M. C.
Published: December 2007

Damaging drillstring vibration has traditionally been associated with resonant behavior of the BHA. As a result modeling has concentrated on harmonic analysis of the drillstring. This has led to strategies for controlling vibrations based on ‘tuning’ the rotary speed and varying weight- on-bit. Using field and laboratory data we demonstrate that, in fact, once initiated, damaging transverse vibrations persist over a wide range of rotary speeds and that they depend on lithology, BHA design and hole gauge. We also show that downhole vibration can lead to increased torque and impaired ROP.

This paper proposes a new mechanism for generating damaging vibration in which the transverse motion of the drillstring couples to the rotary motion during contact with the borewall. This analysis has led to some novel solutions to vibration problems.

We present in this paper field examples of downhole shock measurements together with results from a full scale experimental in- vestigation of the transverse vibration of rotating drill collars to support these con- clusions.
The Design and Testing of Anti-Whirl Bits
Authors: Cooley C. H. , Pastusek P. E. , Sinor L. A.
Published: December 2007

Laboratory drilling tests have been used successfully to determine the tendency of a PDC drag bit to whirl. Drill bit whirl has been demonstrated in all four drilling simulators where whirl tests were performed.

This paper describes the design and testing of anti-whirl PDC drag bits. The verification process of the anti-whirl concept, which includes both laboratory and field tests, will be emphasized. Results from the laboratory drilling experiments that measure a bit’s propensity to vibrate are presented.

Additionally, results from more than 60 field runs are summarized and discussed, with three successful field runs discussed in detail.
Successful Application of the AOBM System in a Deep West Texas Well
Authors: Carter T. S. , Faul G. L.
Published: December 2007

The successful application of an All Oil-Base Mud (AOBM) system improved drilling performance and hole conditions on a deep well drilled in West Texas. The unique design of the AOBM combined with proper bit selection and successful down hole motor runs achieved higher penetration rates compared to offset wells in the area. The liquid phase of this AOBM system was prepared with a low viscosity-low toxicity base oil offering unique properties. This is the first drilling application of this mud design in an area of West Texas where the conventional oil mud system used is formulated with diesel and an emulsified brine phase. This paper reviews the AOBM fluid design, bit hydraulics program, directional drilling operations and associated performance improvements achieved on this well.
Slimhole Drilling Hydraulics
Authors: Delwiche R. A. , Lejeune M. W. D. , Mawet P. F. B. N. , Vignette Roland
Published: December 2007

Drilling in small diameters is not new: the mineral industry currently drills slim holes in hard rocks. In this context, the drill string rotates at high speed very close to the hole wall, which is in general of good stability.

To transfer that drilling method to the oilfield and keeping high rotation speed and small annulus, many problems occur due to the sedimentary type of formations drilled, and hydraulics become crucial for following points of view: the lifting up of cuttings in the annulus (no balling up), the well bore stability, the cleaning of the bit, the differential mud pressure in the annulus, the hydrodynamic lubrication between rods and the well bore.

Therefore, it is essential in slimhole to investigate drilling hydraulics, using basic theoretical equations derived from fluid mechanics.

The developed model takes into account mud rheology, drill string rotation and eccentric position of drill string. Outputs are annulus thickness, drilling parameters (including mud flow), and mud characteristics, all to be respected to reduce slimhole drilling problems. The final output is the compromise which integrates all these requirements for a successful operation.

Tests realized in a slimhole well have allowed to validate the theoretical assumptions.
The Influence of Drilling Conditions on Annular Pressure Losses
Authors: Marken C. D. , He Xiaojun , Saasen Arild
Published: December 2007

Combinations of drill string motion, annular eccentricities and fluid temperatures along the length of the annulus affect fluid flow regimes that control annular pressure losses. In a research well with conventional annular configuration, increases in annular pressure losses were observed to follow increasing drill string rotation. Drill string rotation can result in the formation of centrifugal instabilities that can increase annular pressure losses before the transition to turbulent fluid flow. These instabilities partially take the form of Taylor vortices which lead to irregular fluid flow. Rapid and cyclic changes in rotation rates can lead to synchronous changes in down hole pressures.
Restraining System to Help Contain Well Flowlines and Equipment During Rupture for Increased Safety
Authors: Stromberg J. L. , Surjaatmadja J. B.
Published: December 2007

Typical loads involving energized fluids and ruptured flowlines are much greater than some commonly used restraining devices are capable of handling. Safety considerations demand that this problem be addressed. The restraining system proposed in this paper is one possible method to help address this problem.

The proposed system was designed by modeling the transient and steady-state thrust forces generated by the effluent of energized fluids from ruptured flowlines. The proposed system should help contain the flowline equipment in place in the event of a failure in which a high velocity jet of energized fluid is discharged to the atmosphere.

The thrust forces generated by energized fluids are identified. These forces, together with the kinetic energy of accelerated equipment, have been used to design proposed impact energy-absorption devices.

The proposed restraining system consists of earth anchors, flexible constraints, energy-absorption devices, and flowline attachments. The earth anchors could remain in place throughout the life of the well and thus provide the basis for a restraining system during any subsequent stimulation work.

The proposed restraining system is applicable to onshore wellsites where well stimulation is performed using energized fluids.
U.S. Petroleum Engineering Manpower Supply and Demand
Authors: Miller Mark A. , Wattenbarger R. A.
Published: December 2007

Results of the 1992 SPE Petroleum Engineering Manpower Supply and Demand Surveys are outlined. The supply/demand situation for new petroleum engineering graduates is forecast to worsen in the next two years. Total engineering employment in die upstream sector by large producing companies is expected to decrease by around 15% from 1991 to 1992 and then remain fairly flat through 1994. Employment by the independent and service company sectors is projected to remain flat to slightly increasing, but accounts for a small fraction of total on-campus petroleum engineering hiring. The number of petroleum engineering graduates in 1992–93 is forecast to increase by 30% over 1991–92. during a time when the supply/demand situation is already tightening.
Educating Tomorrow’s Engineers: K-12 The Untapped Resource
Authors: Vetter Betty M.
Published: December 2007

Demographic changes, both in the size and composition of the U.S. school-age population, require preparation of female and minority students as well as white males to be eligible to choose an engineering career. Present achievement levels in mathematics and science for all Americans, and particularly for minority students, require changes in pre-college education.
Engineering Salary Trends in the Petroleum Industry
Authors: Judah J. S. , Lancaster D. E.
Published: December 2007

Results of the 1991 SPE member salary survey indicate that salaries are up 3 to 5% compared to salaries reported in October 1990. Results of the 1992 SPE Starting Salary Survey reflect an increase in starting salaries accepted by B.S. graduates in petroleum engineering to $3,500/month, which is up 4.5% from a year ago.
1990’s Applications of 1950’s Evaluation Technology
Authors: Campbell J. M.
Published: December 2007

In the restructuring process of the petroleum industry let us not forget the basic decision methods which contributed to its current adversity. The emphasis to date has been on the elimination and/or reorganization of personnel. Cutting costs may be expedient on a short-term basis but as a long term strategy, it is merely a step toward going out of business.

As in any intelligent decision process, any examination of our evaluation methods requires understanding their origins, how they changed from then to now, and their current applicability. This paper is a summary of the authors view of these matters.

Hopefully, it will catalyze some long overdue scrutiny of the conventional methods to better understand their current significance, which in turn will result in a new evaluation paradigm.
What Is the Appropriate Return on Investment Required for a Risky Foreign Venture?
Authors: Harrison Robert , Jeffs Paul
Published: December 2007

A method is proposed for determining an appropriate rate of return (ROR) when evaluating exploration and appraisal ventures in different countries. A continuous relationship between ROR and risk is suggested as appropriate for the majority of projects. Overall risk is obtained from a model in which the factors considered to influence the perception of risk are weighted according to their propensity to reduce a venture’s net present value and then combined. The model is used to estimate the appropriate ROR for an Eastern European venture.