bluuebunny/crossref_metadata_2025 huggingface dataset:
Horizontal Wells in a Thick Steeply Dipping Reservoir at NPR-1, Elk Hills, Kern County, California
Authors: Gangle F. J. , Schultz K. L. , McJannet G. S.
Published: December 2007

Two horizontal wells were drilled into a thick, steeply dipping reservoir at the Naval Petroleum Reserve No. 1, Elk Hills, California. The formation beds dip up to 60 degrees in some parts of the reservoir. Drainage of fluids, therefore, into the horizontal sections is along bedding planes and not across them. Under these conditions the cited importance of high vertical permeability in horizontal wells becomes immaterial. In the support of the placement, drilling, and completion of these horizontal wells, reservoir layering and characterization was developed in a detailed form.

The first horizontal well was a medium radius redrill. Drilling and completion problems associated with drilling a new horizontal well out of an old vertical well, drilled and completed in 1951, are given. The second horizontal was a medium radius grassroots well. Both wells have tangent sections at 45 degrees [.78 rad] and horizontal sections placed 40 feet [12 m] above the estimated water-oil contact. The gas/oil contact is about 250 feet [76 m] updip from the horizontal sections. Points of comparison are made between these two types of horizontal wells and offset vertical wells.

Both horizontal wells have shown significant productivity improvement over conventional, vertical wells. Typically, conventional wells are produced at several hundred barrels of oil per day to control excessive gas production from this pressure maintained reservoir; however, the horizontal wells produce over 1000 barrels [159 m3] daily at solution gas. The cost to drill and complete these horizontal wells was double conventional costs, but the improved oil recovery from them will amount to an estimated 10 million barrels [1.6 million m3] of additional oil per well, not otherwise recoverable from conventional vertical wells. The potential for improved oil recovery overall, therefore, from horizontal wells could lead to an ultimate oil recovery as high as 70 percent of the estimated 382 million barrels [61 million m3] originally in place (OOIP).
Predicting Horizontal Well Performance: A Review of Current Technology
Authors: Norris S. O. , Hunt J. L. , Soliman M. Y. , Puthigai S. K.
Published: December 2007

This paper presents a comprehensive review of current petroleum literature focusing on the reservoir engineering aspects of horizontal well technology. The objective of the paper was to provide the engineer/scientist with an overview, discussion, and where appropriate, recommendations for the following areas: (1) analytical solutions for one-phase flow; (2) water or gas cresting; (3) numerical simulation; (4) hydraulic fracturing; and (5) well test analysis. Some of the more simple equations are given in the paper, while complex solutions are thoroughly referenced for detailed study.
Operator Management Of A Comprehensive Drilling Safety Program With Participation Of Contractors
Authors: Hinkel Robert M. , Abernathy Lucian M.
Published: December 2007

Both operators and contractors have greatly Increased their loss prevention efforts in recent years. However one of the toughest problems has been to overcome the lack of true operator involvement in coordinating and enforcing safety programs on drilling projects involving multiple contractors supplying different services. Drilling contractors have complained that untrained service personnel and a lack of operator support undermine their programs. On the other hand, operators and service companies often accuse the drilling contractors of not enforcing their policies and programs at the rig site.

Unocal's Western Region Drilling Department has taken the approach that only the operator can truly coordinate and enforce multi-contractor safety. programs at the rig site. We have implemented a comprehens ive, cooperative program over the past three years. This paper will describe our efforts in detail and explain how we work to coordinate different contractor loss prevention prograsm from the initial service contract through a post-operation review after the well has been drilled. We will emphasise the specific programs that have been implemented to make safety the number one priority of all personnel at the rig site regardless of employer. This paper will also include examples of multi-contractor statistical data that provide a true picture of safety performance.
Creating a Quality Culture in an International Corporation
Authors: Myers G. , Heppenstall B.
Published: December 2007

Since the early 1980's, many US-based companies including those serving the oil industry, have become increasingly aware that a business built on a quality culture will greatly enhance their ability to serve the customer, while leading the way to a technological breakthrough and systematic improvement of the industry itself. The methodology for managing quality has proven similar for most companies of that period in that responsibility for quality was delegated to specialists., both internal and external.

After years of disappointing results, accompanied by internal divisiveness and impacted by a severe downturn in market conditions within our industry, a new direction with respect to quality was launched.

The genesis of this new direction has taken place within the last few years. Generally, it has taken additional time for a critical mass of the management team to gain a better understanding of its role and responsibility with regard to leading the company in a way that focuses on customers. Still, many organizations, steeped in former methods and priorities, have resisted the attempt at unification through the implementation of a company-wide quality process.

This paper examines the struggles of such companies with respect to the evolving customer-focused, quality culture. It highlights why there may be difficulty gaining the commitment of upper and middle managers, and suggests methods of transforming these individuals into quality-driven business leaders. The role of the quality professional in facilitating the transformation process is examined throughout the paper.
New Tool Improves Ability To Run Casing in Long Sections of High-Angle Boreholes
Authors: Sangesland S. , He Xiaojun
Published: December 2007

A new tool has been developed to make it easier to run casing in long sections of high-angle and horizontal boreholes. The key element in the system is a telescope joint integrated in the casing string. By using the gravity force, hydraulic force and friction force, the two sections of the casing string can be moved separately step by step to the target. Calculations show that the running length of the casing string can be increased significantly in long sections of high-angle boreholes.
The Design of an Automated Drilling Rig: RA-D
Authors: Kennett B. J. , Smith M.
Published: December 2007

This paper describes the design of an automated drilling rig (RA-D) and identifies the design methods and techniques used to produce an integrated drilling system incorporating a compact automated drilling rig and pipe handling system.

The innovatory nature of the concept lies in the technical configuration of the system, the reasoning behind the specification and the method used to develop the concept.
Human Factor Considerations for Design of Drill Floors
Authors: Larsen F. P. , Wood J. E. , Pethick A. J.
Published: December 2007

This paper outlines a study which provided an ergonomic guidelines document for drill floor designers, produced through a systematic process of information collation and analysis to give practical ergonomic assistance aimed particularly at early design stages.
Drilling a Medium-Radius Horizontal Well With Aerated Drilling Fluid: A Case Study
Authors: Claytor S. B. , Manning K. J. , Schmalzried D. L.
Published: December 2007

Many formations throughout the world are sensitive to oil and water based drilling fluids and are best drilled with air as the drilling medium. However, positive displacement motors do not typically operate well with air. In addition, mud pulse telemetry MWD tools will not operate reliably in an air environment. In the second quarter of 1990, Marathon Oil Company successfully drilled a medium radius horizontal well in Jackson County, Michigan using an aerated mud system and an electromagnetic telemetry link MND tool. This paper will describe the pre-well planning and practical aspects of drilling the well with emphasis on the hydraulic system and drilling fluid mixture.
Design And Operation Of Sea Water Injection Systems
Authors: Cole William I.
Published: December 2007

This paper was prepared for the 43rd Annual Fall Meeting of the Society of Petroleum Engineers of AIME, to be held in Houston, Tex., September 29-October 2, 1968. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made.

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

This paper summarize the planning, design, and operation of water injection projects utilizing water taken from the projects utilizing water taken from the Gulf of Mexico. Feasibility of a system to properly and economically condition sea water for injection is reviewed. It is shown that water could be successfully injected if it is chemically stable, sterile and properly filtered.

Design of an economical system for properly conditioning the sea water is properly conditioning the sea water is discussed. The control methods for dissolved oxygen, pH, calcium carbonate deposition, bacterial growth, and suspended solids are presented.
Evaluation of New Tool Joint Hardfacing Material for Extended Connection Life and Minimum Casing Wear
Authors: Marx C. , Retelsdorf H. J. , Knauf P.
Published: December 2007

New wear resistant materials for hardfacing of tool joints have been developed and were successfully tested under relevant conditions at the Institute of Petroleum Engineering (ITE) of the Techn. Univ. Clausthal, Germany.

Out of a total of eight new products two combinations of hardmaterial and bond were very positive with respect to following two criteria: -low wear figures for the protected tool joint in very abrasive formations and-low casing wear due to axial and rotating interaction of the protected tool joint under radial loads (5-1/2" tool joint in 9-5/8" casing Grade C-90)

The new products show drastic improvements with respect to earlier results under similar test conditions.

Results are presented in OD-wear of tool joint and reduction of wall thickness of casing material with respect to distance slid, i. e. in pm/km.

A new testing facility allowing a combination of axial movement and rotation was used. Beside casing material Grade C-90 abrasive Silicon Carbide (SiC) material shaped to 8-1/2" borehole contour with a contact length of 10 inch were used.
Screening Waterfloods for Infill Drilling Opportunities
Authors: Fuller S. M. , Sarem A. M. , Gould T. L.
Published: December 2007

Infill drilling is now recognized as a viable improved recovery process. However, the reliable prediction of incremental recovery by infill drilling cannot be readily and accurately determined by present techniques.

As an alternate approach, a DOE sponsored infill drilling predictive model (IDPM) was evaluated. Its performance was improved by x2adjusting some of its key parameters based on the comparison of actual field recoveries with model results.

Also discussed in the paper is the sensitivity of infill recovery to areal and vertical heterogeneities. Also highlighted is the importance of applying remedial techniques is highlighted, such as near well plug backs and in-depth mobility control upon the recovery efficiency.
Optimization of Field Development Through Early Acquisition of 3D Seismic
Authors: Myers R. C. , Rijks E. J. H.
Published: December 2007

3D seismic is a powerful and cost-effective geophysical technique to acquire data from which detailed structural and stratigraphical information can be extracted. It generally allows a realistic evaluation of reserves and uncertainty ranges required to optimise field development planning. Such a realistic quantification of uncertainties is a pre-requisite in the application of probabilistic techniques for gross hydrocarbon rock volume estimation. Consequently, the acquisition of 3D seismic at an early stage, i.e., directly following the drilling of a discovery well, is strongly recommended.

Although the cost of 3D seismic is, in some cases relatively high, the incremental cost per barrel is generally small when compared to the costs of "dry" or misplaced wells and of sub-optimal development of a field. Techniques have been developed to reduce acquisition and processing costs as well as to speed up interpretation procedures. Horizon-oriented interpretation, using automatic volume tracking programmes and attribute extraction techniques, has proven to be a fast and efficient way to outline subtle geological detail.

3D seismic interpretation greatly improves the delineation of fault blocks and the understanding of fluid and pressure communication. It has generated new prospects below and adjacent to developed fields, generally resulting in an increase in reserves, especially in structurally complex settings with stacked reservoirs.

3D seismic has contributed significantly in improving the validity of fault seal investigations by juxtaposing slices of 3D seismic data parallel to and on either side of a fault plane. These fault slices have been used to display juxtaposition across faults of seismic amplitudes related to lithology and/or hydrocarbons.

The information obtained from 3D seismic, when using these advanced interpretation techniques, is even more essential in the planning of expensive horizontal wells, which play an increasingly important role in field development.

The importance of early acquisition of 3D seismic will be illustrated by examples from several major hydrocarbon provinces in which the Shell Group is active.
A New Approach to Decision Making in Reservoir Engineering
Authors: Zolotukhin A. B.
Published: December 2007

A new approach to the decision making in reservoir engineering based on application and development of modern methods of a systems analysis and multicriteria optimization under condition of incomplete and fuzzy information is made.

A special attention is paid to the methodology of a design stage of oil and gas fields development which helps to formulate the main goals of exploitation, to find a set of problems to be solved to get the best project solution and the methods of their solution most suitable for each particular problem.

An approach to a selection of EOR methods based on a fuzzy sets theory is described. It allows to differentiate the reserves on a basis of applicability level of each EOR method under given geological conditions.

The other problem solved is how to determine the best system of wells location within the reservoir. Based on a combination of statistics and theory of a dimension analysis such a method allows to build a pareto-optimal set of wells spacing and can be used both at the design stage and for the analysis of oil recovery process.

There is shown a technique of multi-criteria optimization to get the project solution which is the best one on the set of goals which should be reached during exploitation period of an oil field.
Defining Data Requirements for a Simulation Study
Authors: Dandona A. K. , Alston R. B. , Braun R. W.
Published: December 2007

This paper addresses the importance of timely data collection for proper reservoir management using simulation as a tool. Data requirements for black-oil, compositional and steam simulation have been documented. The interplay between various geosciences and the proper translation of data ensure the success of such an effort.
Nitrogen Injection vs. Gas Cycling in Rich Retrograde Condensate-Gas Reservoirs
Authors: Siregar S. , Hagoort J. , Ronde H.
Published: December 2007

The common method to prevent condensate from dropping out in gas-condensate reservoirs that are produced by pressure depletion is gas cycling: the reinjection of produced dry gas. However, dry gas is expensive and is not always available. An alternative could be nitrogen, which is available everywhere, relatively cheap and has favourable injection characteristics (safe, non-corrosive, environment-friendly).

The problem with nitrogen injection, however, is that it may lead to significant in-situ condensate drop-out due to the mixing of nitrogen and gas-condensate in the reservoir. The objective of the study reported in the paper is to investigate whether nitrogen injection can be applied as an alternative for gas cycling, with emphasis on the condensate drop-out problem.

The investigation comprised three phases:

Formulation of a rich gas-condensate, consisting of methane, n-butane, n-tetradecane and nitrogen, using an interactive PVT simulator. Calculation of liquid drop-out for both dry gas and nitrogen injection as a result of mixing, by varying injection gas concentration. Evaluation of displacement efficiency by using a compositional one-dimensional simulator for various Peclet numbers.

The chosen gas has common field characteristics (Gas Liquid Ratio = 2300 V/V, API gravity = 58.6) and is rich (shown by the maximum liquid drop-out of 30%). Liquid drop-out as a result of mixing is much higher for nitrogen (max. 25 %) than for dry gas process (max. 2%). Displacement calculations show that, at low Peclet numbers, nitrogen injection results in much poorer displacement efficiencies than dry gas injection. However, the difference decreases significantly at increasing Peclet numbers.

The main conclusion of the paper is that, under field conditions, nitrogen injection could be a viable alternative to dry gas cycling. Nitrogen injection may find application in the production of condensate reservoirs in areas with a well developed gas market where dry gas is not available for injection. The main contribution of the paper is that it highlights and provides information on a relatively new process for the exploitation of condensate fields.
The Use of Ultramicrobacteria for Selective Plugging in Oil Recovery by Waterflooding
Authors: Cusack F. M. , Singh S. , Novosad J. , Chmilar M. , Blenkinsopp S. A. , Costerton J. W.
Published: December 2007

While the use of bacteria to plug the high permeability zones that cause water breakthrough in waterflood operations has been suggested repeatedly for several decades, field operations have met with only intermittent success. We have used starvation to reduce normal-sized (±1.0 μm), naturally adherent, vegetative bacterial cells to very small (±0.3 μm), non-adherent ultramicrobacteria (UMB) that penetrate rock and sand matrices very readily. When UMB are injected into sand or rock >180 milliDarcies inpermeability, these very small, non-adherent cells are readily transported deep into the pore spaces. As they penetrate, some UMB are retained in the pore structures and, when the matrix is flooded with a suitable nutrient, these small, starved cells return to their full vegetative size and their normal high level of exopolysaccharide slime production. Within days of nutrient flooding, the permeability of the bacteria-treated high permeability zones is reduced by at least 99%.

This novel biotechnology is presently being licensed for field testing in the prevention of coning and in the selective plugging of high permeability zones in waterflood operations.
Directional Trajectory Control by Employing Statistics and Probability Methods
Authors: Xu Hong , Zhang Jun , Jiang Chuanxin
Published: December 2007

In accordance with the conception of regarding the drilling process of individual well as the reciprocal full scale simulation of others, this paper describes the processes to extract pertinent information for trajectory control from the database of accomplished wells and drilled sections. The references have been made to the successful application in a cluster-well engineering, in terms of H50 project, to validate the related methods.
Reservoir Engineering Issues of Horizontal Hole Development
Authors: Niko H.
Published: December 2007

This paper describes important reservoir engineering issues of horizontal hole drilling in primary field development, highlighting the areas of productivity Improvement In tight reservoirs and oil rim development. Factors influencing the productivity improvement over that of vertical wells In tight reservoirs are discussed, e.g. horizontal hole length, permeability anisotropy ratio, well location with respect to areal boundaries, hydraulic fracturing and mechanical skin factor. In the area of oil rim development, a discussion on critical rate models (including one which includes pressure losses In the borehole) Is given for gas/oil systems, whilst also showing how the critical rate concept can be used for production forecasting. Applications of numerical simulation are described for more complex geological models for oil rims with both gas cap and active water drive. Among the factors influencing the production performance of horizontal wells in oil rims, oil mobility, drainage area, vertical well position in the oil rim/strength of water drive, well length, permeability anisotropy ratio or the presence of dipping shale layers are described. Well testing is discussed next as a way of obtaining critical parameters such as permeability anisotropy ratio and mechanical skin. Finally a summary of field applications in areas where Shell has an interest is given.
Reservoir Evaluation of Horizontal Bakken Well Performance on the Southwestern Flank of the Williston Basin
Authors: Reisz M. R.
Published: December 2007

This paper presents the results of a reservoir performance study for horizontal and vertical Bakken wells in the "Fairway" of the Williston Basin. A combination of forecasting methods were utilized, including decline curve analysis, material balance, analytical solutions, and empirical correlations.

The results indicate that recoverable reserves from horizontal wells in the "Fairway" are 2.5 to 3.0 times a vertical well for 1.5 to 2.0 times the cost. Simple theoretical calculations combined with field data are useful in making initial estimates of original oil in place, recoverable reserves, and drainage area.
Application of Foam Fluids To Minimize Damage During Fracturing
Authors: Harris P. C.
Published: December 2007

High quality foam was developed as a premium cost fracturing fluid in the past decade, but many beneficial properties of foam may make it the fluid of choice for hydraulic fracturing in the 1990's.

Foam fluids were first applied to gas reservoirs having low pressure, since gas in the foam expanded after the treatment to remove the fracturing fluid from the well, minimizing damage to the formation. But foams have also been applied to all types of wells, low or high pressure, gas or oil, where it was important to minimize damage. The low liquid content of foams leaves less liquid to remove from the well.

Foam fluids have low fluid loss to the formation. In addition, the gel filtercake which is deposited on the formation face during fracturing is substantially thinner than filter cakes deposited by other fluid types such as crosslinked polymer fluids. Damage to fracture conductivity is minimized.

The two-phase structure of foam fluids allows the generation of high viscosity fluids for fracture propagation, and its yield point characteristics provide enhanced proppant transport. Mathematical relations can calculate the foam composition required for specific applications over a broad range of gas qualities, temperatures, and polymer concentrations.

The development and application of constant internal phase design concepts allow proppant to be added to a foam fluid while maintaining viscosity constant. High proppant concentrations can be carried with constant internal phase foams while minimizing frictional pressure losses.

This paper discusses the relationships of rheology, fluid loss, constant internal phase design, and fluid recovery in application of foam to hydraulic fracturing.
Increasing Arun Well Deliverability Through Effective Acid Fracturing
Authors: Cannan W. L. , Jennings A. R. , Huseini S. , Bordelon T. P. , Sardjono S.
Published: December 2007

The prolific Arun Field in North Sumatra, Indonesia continues to produce substantial amounts of natural gas and condensate. The massive carbonate reef reservoir is beginning to require special measures to maintain deliverability to recover the large quantities of hydrocarbon remaining in the formation. Optimization of production from the Arun will demand combined efforts from Arun geologists, reservoir, production and operations personnel, as well as technical advisors.

Although Arun wells typically produce 40 to 100 MMSCFD/well, many of the wells have positive skins, indicative of near wellbore formation damage. In most of the field, the lower portion of the Arun has less effective permeability than the upper part. In other wells, high permeability zones are interspersed among more massive low permeability intervals. Well stimulation by acid fracturing can be effectively used to remove damage effects (induce a negative skin), provide highly conductive flow channel for improved flow from low permeability intervals and enhance flow from high permeability zones.

Six wells have been successfully stimulated by acid fracturing in the Arun Field. the stimulations and results will be discussed in detail.
Production Logging in a Rod-Pumped Well Using Coiled-Tubing-Conveyed Tools and Nitrogen Gas Lift
Authors: Mason D. L.
Published: December 2007

This paper describes the principles of coiled tubing production logging and describes the first application of this method - on Wytch Farm lA-01BP - and describes the results that were obtained. The well was successfully gas lifted using this method and the technique of coiled tubing production logging was successfully demonstrated.
Petroleum Engineering Teaching Effectiveness With Field Practitioners in Classrooms
Authors: Sharma M. P. , Harris H. G.
Published: December 2007

Engineering educational institutions have a dominant role to play in shaping the future course of energy and mineral industries. When researching and defining the needs for educating engineers for the next century, Gentry (1) has concluded, "we must develop and implement educational experiences, both in the classroom and the research laboratory, that enable students to keep pace with the world and the technological, social, political, and economic initiatives that drive it."

In its "University-Industry-Government (UIG) Partnership for Quality Engineering Personnel" program announcement (2) the National Science Foundation noted three major impediments to maximizing the quality of engineers produced by some of our academic institutions. "One of them being failure to incorporate major elements of engineering practice into engineering curricula". Apparently the incorporation of such a factor in classrooms has been a matter of high importance in the NSF Engineering Infrastructure Development Program office recently. This paper addresses and investigates some of the aspects of such a practice from teaching principles as well as methodology points of view.

There are many ways one can define "Teaching" and still not be satisfied with the completeness and certainty of these definitions. The reason lies in the fact that the process of teaching involves art, science and humans. Madeline Hunter (3) tries to explain nature of teaching very succintly: "Educators have finally arrived at the point that professionals in medicine achieved when the latter discovered that germs and not evil spirits were causing much of the problem. We now know many cause-effect relationships in teaching and learning. As a result, we can use those causal relationships to promote student learning in the same way the doctor uses his medical knowledge to promote health. In both education and medicine we are learning more each day even though there still remains much we don't know."
Development Planning of Seligi Field Offshore Pensinsular Malaysia
Authors: Yong T. O. Aw , Soffian R. M.
Published: December 2007

The Seligi field is the largest oil field in Peninsular Malaysia. Its largest reservoir, the J-18/60 which contains about 47 percent of the field's total original oil-in-place, has a relatively thin oil column (19 to 36 meters) overlain by multiple large gas caps and underlain by an active aquifer system. The sandstone thickness and reservoir quality vary across the field. Three other major oil-bearing reservoirs also have thin oil columns and gas caps. The J-18/60 is being produced via a combination of gas cap expansion and waterdrive mechanisms. Optimum recovery will depend upon proper balancing of crude withdrawals and gas injection. The production strategy is also complicated by the fact that the aquifer underlying the major J-18/60 reservoir is common to other fields which have been on production for several years.

This paper discusses: 1) the reservoir development planning of Seligi, which involved the development of a very large computer simulation model to assist in addressing the numerous complex factors that influence oil recovery and hence development decisions, 2) evaluation of horizontal wells to optimize recovery from the thin oil column and experience in drilling the first horizontal well in the field, and 3) challenges in facilities planning for development of the field.
Comparison of Results From an Advanced Gas Kick Simulator With Surface and Downhole Data From Full Scale Gas Kick Experiments in an Inclined Well
Authors: Rommetveit R. , Vefring E. H.
Published: December 2007

The RF kick simulator is a tool for well control engineering, study and training. The simulator accounts for all important physical effects related to a kick, and models kicks in both water based mud and oil based mud. In order to test the performance of the model, real gas kicks in both water based and oil based mud have been simulated. Surface and downhole data from full scale gas kick experiments have been used to verify the simulator. The data used are downhole annulus pressure data, surface pressures, mud flow rate out, pit gain and gas transport data. The measured gas influx rate into the well versus time has been used as input data to the gas kick simulations.

The conclusion of the comparisons is that the RF kick model reproduces real kick data with acceptable accuracy. This confirms the capability of the RF kick simulator to model gas kicks. The simulator can therefore be used with confidence for the design of well control procedures and the evaluation of kick situations.
Pressure Gauge Specification Considerations in Practical Well Testing
Authors: Veneruso A. F. , Erlig-Economides C. , Petitjean L.
Published: December 2007

This paper addresses the characterization and consequences of non-ideal pressure gauge performance on pressure transient analysis. In practice, pressure measurement instruments can have response errors, including short and long term drift and anelastic relaxation, that can dramatically affect calculation of even the most basic reservoir and wellbore properties such as producibility, permeability, average reservoir pressure, and the wellbore skin factor. Best results are obtained when the pressure gauge is selected with an eye on the intended application because different types of instruments have different response characteristics.

To determine how the pressure gauge affects well test analysis, a transfer function approach is used to characterize the gauge response to changes in wellbore pressure. This model is based upon published specifications, measurement quality controls, and the fundamental physics of commonly-used transducers. This transfer function approach can also be generalized to include temperature response effects as well as the effects of noise and non-ideal gauge electronics and processing.

Specific field examples are given to illustrate how these gauge response errors affect the analysis of pressure buildup tests using the basic Homer approach as well as some of the latest computer regression techniques. Error bounds on the results of reservoir and wellbore parameter analysis are computed using a range of different gauge specifications.

The results of this approach are used to show how to optimize testing performance with cost-effective instrumentation.
Use of Radioactive Isotopes in Gas injection
Authors: Calhoun Tom G. , Tittle Robert M.
Published: December 2007

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.

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

Introduction

Major advances in the measurement of extremely small amounts of radiation make the use of radioactive isotopes as a tracing material in petroleum reservoirs practical. Isotopes, Inc. has developed equipment capable of extremely low level techniques which, together with a number of low cost radioactive isotopes, make possible many useful applications in reservoir engineering.

RADIOISOTOPES AS TRACERS

By introducing radioisotopes in the injection wells with the injected gas it is possible to "tag" the injected gas and, by analyzing produced gas, to trace the movement of the injected fluid throughout the reservoir. Directional permeability may be identified early in the life of the project so that steps can be taken to maximize project so that steps can be taken to maximize recovery efficiency.

The use of tracers to follow movement of gas, oil, or water is not new. Underground tracer work has utilized many materials; among them certain dyes and chemical compounds, helium, and carbon monoxide. The problems are the same in every application:

To get the tracer to behave identically with the material traced To obtain adequate sensitivity To carry out the tracer project at reasonable cost

Differences in adsorption, absorption, wetting, precipitation etc., between the tracer and the precipitation etc., between the tracer and the fluid to be traced cast doubt on the results on many of the earlier tests. These tracers also lacked sufficient sensitivity. Such factors discouraged the use of tracing techniques, even though it has been obvious since the beginning of secondary recovery that an ideal tracer would be useful in almost every operation.

In principle, radioactive isotopes constitute ideal tracers; first, because the fluid itself may be made radioactive, or the tracer can be made a part of the fluid chemically. For instance, tritiated hydrogen acts the same as hydrogen because it is, in fact, a part of the hydrogen molecule. The only difference is that one of the hydrogen atoms in the H2 molecule has been replaced by a tritium atom. Tritium is an isotope of hydrogen, having two extra neutrons in the nucleus. Tritium has a half life of 12.5 years, and low level counting techniques make possible the detection of these isotopes through seven half lives or approximately 85 years. A number of other low cost radioisotopes are available for use in gas injection projects.
Pipe Coupling Techniques for Marine Pipelines
Authors: Thielhelm Harry W.
Published: December 2007

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.

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

Over 100 years ago, man conceived the idea of transporting petroleum liquids through pipe and petroleum liquids through pipe and successfully laid a 6 mile long line. Since that time he has solved problems of new materials, met many problems of new materials, met many challenges of terrain, and continually improved and expedited the process of joining two sections of pipe, installing connections and making repairs. Pipelines throughout the world are monuments to his success.

Now a new and difficult problem confronts the designer and pipeliner: the successful installation and operation of offshore pipelines in waters of ever-increasing depths

This paper presents a review of the methods and fittings developed for pipelines on land, discusses their suitability for underwater installations,, and reveals the new methods and fittings prepared specifically for underwater lines.

Introduction

Ever since man conceived the idea of transporting liquids through pipe, he has been confronted with the pipe, he has been confronted with the problems of changing materials and problems of changing materials and site environments, and challenged by pressures to improve and expedite the pressures to improve and expedite the process of joining two tubular process of joining two tubular sections, installing connections, and making repairs.

In 1865, the first petroleum pipeline was connected by screwed pipeline was connected by screwed joints and the general reaction was that a major advance had been made. It was a 2-inch cast iron line, six miles in length, not a big accomplishment by our present day standards but of utmost importance at that time. Since then many developments have been made in pipelaying connections that not only pipelaying connections that not only improved the speed of installation but also the quality, service life, maintenance and repair of completed lines.

Today there are few, if any, nations that are not spanned with a multitude of varied sized lines carrying numerous types of fluids.
An Investigation of the Damaged Zone Created by Perforating
Authors: Pucknell J. K. , Behrmann L. A.
Published: December 2007

Underbalance perforation flow experiments were performed on reservoir and outcrop sandstones to investigate the perforation damaged zone. Cores from several different formations were perforated under reservoir conditions. After perforating, the cores were examined using CAT scans (Computer Aided tomography), thin sections and mercury porosimetry. In conjunction with these measurements, permeabilities in the damaged zone were measured using a mini-permeameter and radial flow permeameter or were estimated from pore size distribution.

The density and porosity of the damaged zone (at least for saturated rocks) is essentially the same as that in the undamaged rock. The damaged zone is not compacted, contrary to suggestions made in earlier work. However, the creation of this zone involves the destruction of large pores. The volume lost from these pores is replaced by microfractures created when rock grains are fractured by penetration of the shaped charge jet. This reduction in the average pore size causes a reduction in the permeability within the damaged zone. Although direct measurement of this permeability was made difficult by naturally occurring permeability variations, unambiguous measurements were obtained.

Based on this work an understanding of the factors which control the permeability in the perforation damaged zone is advanced.
Petrophysical Evaluation Of The Smackover Formation In East Texas
Authors: Ritch H.J.
Published: December 2007

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.

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

Significant amounts of hydrocarbons are produced from dolomite and limestone reservoirs produced from dolomite and limestone reservoirs in the Smackover formation in East Texas. The major contributor of these produced volumes and reserves are the dolomites consisting primarily of oomoldic and sucrosic rock types. The oomoldic rock type is the most significant. Predominant limestone rock type is oolitic Predominant limestone rock type is oolitic grainstone. Porosity development is mainly secondary for all rock types. Electrical and acoustical properties are different for the dolomite and limestone lithologies. The residue hydrocarbon trapping characteristics of reservoir quality rock are high as determined by various techniques.

Introduction

The hydrocarbon productive Smackover formation of Jurassic age in East Texas has been and will be a prime exploratory objective for a number of years. The geographical area covered by this paper is shown in Figure 1. The Smackover formation is overlain by the Buckner and underlain by the Norphlet, all of Jurassic age. The Smackover pinches out updip to the north and west of the Talco-Mexia Fault line. Hydrocarbon accumulations appear to be limited downdip by the absence of porosity development. Numerous gas-condensate and oil fields have been discovered with the larger being Bryans Mill, New Hope, Como and Northeast Edgewood. The larger fields have been found in a band almost midway between the updip porosity pinchout and downdip limit of porosity development.

The standard open hole logging program consists of running the induction-electrical and the acoustical velocity surveys. Additional surveys often utilized are natural gamma-ray, gamma-gamma density, neutron (conventional and contact) and microlog surveys. It has been found that for wells drilled with normal water base muds (density 10.0–10.5 pounds per gallon, 8–10 cc fluid loss and 40–50 pounds per gallon, 8–10 cc fluid loss and 40–50 seconds viscosity), filtrate invasion is quite shallow, usually less than two hole diameters.

The first porosity development below the top of the Smackover is normally open hole drill stem tested, particularly in exploratory wells. The objectives of drill stem testing are (1) determine fluid content and (2) rate of fluid production.

In order to efficiently exploit these accumulations, the amount and distribution of the hydrocarbons initially present as well as the most efficient method of recovering these hydrocarbons needs to be known. This paper defines some of the petrophysical parameters used to evaluate the Smackover and points out difficulties not yet resolved.
Heterogeneity in a Complex Turbiditic Reservoir: Impact on Field Development
Authors: Alabert F. G. , Corre B.
Published: December 2007

In a previous paper [1], a geological/geostatistical methodology has been presented to model heterogeneity in a complex turbiditic formation. The methodology is based on geostatistical conditional simulation techniques that allow building 3D models of geological heterogeneity. The next step consists in translating such stochastic models of heterogeneity into models of flow properties for reservoir simulations. The present paper describes the approach that has been followed to achieve that goal. It includes two steps: a first one, to translate the fine grid geological models of heterogeneity generated in [1] into fine grid petrophysical models,a second one, to upscale the fine grid petrophysical models into coarser grids of effective flow parameters for full-field simulations.

The procedure requires precise methods for averaging absolute and relative permeabilities. A new technique for averaging relative permeabilities and capillary pressures is presented.

The procedure is validated by the available dynamical data (well tests and a 25 years production history).

The integrated geological-geostatistical-upscaling strategy described in [1] and in the present paper is shown to be particularly useful to reservoir history matching and monitoring, as well as to evaluate uncertainties on reservoir performances in undrilled areas of the field.
The Kurunda Field Tirrawarra Reservoir: A Case Study of Retrograde Gas-Condensate Production Behavior
Authors: Hueni G. B. , Hillyer M. G.
Published: December 2007

The Kurunda Field, Tirrawarra sandstone is a low permeability, lean gas condensate reservoir located in the Cooper Basin of South Australia. Prior to production consideration was given to the need for gas cycling to maximize liquid recovery. Early long-term production tests, however, showed a much larger drop in liquid-gas-ratios than expected. A study was undertaken to determine the cause of this drop and the implications with respect to future operational policy.

A comparison of field observed performance and laboratory data indicated a reservoir fluid composition intermediate between that measured on two laboratory samples. Field observed performance together with results from a simplified model of retrograde gas condensate reservoir behavior further indicated that the observed liquid-gas-ratio correlated more closely to the bottomhole flowing pressure rather than the average reservoir pressure. This liquid-gas-ratio behavior was found to result from the near wellbore region of the reservoir acting as a separator and preventing the recovery of liquids originally entrained in the gas. This separation effect which continues for the life of the reservoir adversely effects liquid recovery for both primary and pressure maintenance operations, and prevents the economical application of the latter activity.
Saladin Reservoir Management
Authors: Morrison G. R. , Gorjy F.
Published: December 2007

This paper provides a case study for the reservoir management of the highly productive Saladin Field. It covers the Reservoir Engineering aspects of the development from discovery through to present day reservoir monitoring, reserves optimisation and infill evaluation.
Gravel Packing in High-Rate Oil Completions
Authors: Shucart J. K. , Rustandjaja A. F.
Published: December 2007

Forty nine high rate oil wells were completed with gravel packs in Maxus' Intan/Widuri fields in a nine month period. Lower than expected productivity on the initial completions resulted in an extensive investigative test program conducted primarily at the field level. The test program, the procedures used and the results of these tests are reviewed. The investigations include fluid and gel compatibility with the formation, determination of the critical gravel pack slurry parameters, pressure losses across different screen types, and the outcome of various gravel placement techniques.

The primary conclusions are as follows. Slurry gel viscosity was the most critical parameter in the amount of gravel placement. Perforation washing in conjunction with underbalanced tubing conveyed perforating (TCP) gave significantly better gravel placement and productivity than only underbalanced TCP. The use of a short cleanup test following completion is beneficial in early identification of a production impairment.