bluuebunny/crossref_metadata_2025 huggingface dataset:
Drilling Related Performance
Authors: Walker S. , Coumans H.
Published: December 2007

Control of capital expenditure on drilling/completion operations is important. In many instances the cost of drilling has meant that projects were deferred or cancelled completely. This paper discusses the factors which should be considered in reducing drilling/ completion costs by improving performance in the well pre-planning to well on production, cycle.

Major technological advances in equipment utilised in all aspects of drilling operations are also discussed, highlighting their benefits.

The use of computers for handling and storage of information can assist in the task of analysing drilling performance. An accurate database is of overriding importance and fundamental to being able to define where improvements can be made. A recent case history of one of Shell International’s operating companies is discussed as an example of the techniques employed in analysing performance and data are presented to illustrate the points made.

In a large international company such as Shell, with exploration and development drilling operations worldwide, some means of ensuring that operating departments learn from each other is also required. Performance indicators were developed to assist both operating departments and specialists in Shell Central Offices in The Hague to accomplish this. The benefits of such indicators from the drilling/completion performance aspect are discussed and numerical examples are given which illustrate how such indicators may be used to pinpoint adverse trends.
Wellsim and Pepite: Accurate Models of Multiphase Flow in Oil Wells and Risers
Authors: Roux A. , Corteville J. , Bernicot M.
Published: December 2007

Two mechanistic models for multiphase flow calculations are presented. They result from a 10 year research program and predict pressure and temperature profiles in oil wells and pipelines.

These models are based on the theory of fluid mechanics and on experiments carried out in oil industry conditions. The experimental facility consists in long testing lines, 3 and 6 inches in diameter, inclinable from 0 to 90°. Liquid hydrocarbons, water and natural gas have been used to generate multiphase flow at pressures up to 50 bar.

Results of these models have been compared with field data gathered on producing wells and pipelines. A better accuracy is obtained than with conventional methods.
A Practical Approach for Determining Permeability From Laboratory Pressure-Pulse Decay Measurements
Authors: Dicker A. I. , Smits R. M.
Published: December 2007

A new pressure-pulse decay method is presented to measure permeabilities of tight rock samples. Existing pressure-pulse methods yield pressure decays which are either slow or difficult to analyse. Often approximations are made which may yield considerable errors in the derived permeability values. The new method is simple and enables very fast and accurate permeability measurements.

The exact solution of the differential equation describing the decay curve resulting from a pressure-pulse measurement was analysed in detail. This showed how the decay curve is influenced by various parameters in the design of the pressure-pulse permeameter. In this way various existing designs could be compared. Furthermore, the analysis showed how a pressure-pulse permeameter should be designed such that the measured decay is fast and simple to analyse. Also an approximate solution was obtained which is accurate to within 0.3% of the exact solution which is much more difficult to handle. Using this solution a new and simple analysis procedure was developed. Combining the new design with the new analysis method results in an elegant method for fast and accurate pressure-pulse measurements.
An Overview of Horizontal Well Completion Technology
Authors: Cooper R. E. , Troncoso J. C.
Published: December 2007

Highly deviated or horizontal wells have led to new thinking in the application of well completion and stimulation technology. Horizontal drilling technology has advanced rapidly over the past few years. It is now common to be able to drill and control horizontal holes of greater than 1,000ft. displacement. However, horizontal completion technology is still on a steep learning curve and many completion practices need to be refined to contribute to the economic success of a horizontal project. In addition, a better understanding of reservoir performance with horizontal completions will be needed.

Proven completion techniques used in less deviated wells have not proved to be cost effective or efficient in this new application. This paper addresses several of these problem areas by discussing the shortcomings of vertical well completion technology and offers solutions to horizontal applications.

Specific completion areas discussed include production string isolation, influence of horizontal wellbore deviation, stimulation considerations, sand control and downhole production equipment. Case histories of three Bima Field wells, offshore Indonesia, are presented to illustrate various completion practices.
Selective Emplacement of Xanthan/Cr(III) Gels in Porous Media
Authors: Chang P. W. , Burkholder L. A. , Philips J. C. , Ghaemmaghami M. , Myer M. A. , Babcock R. E.
Published: December 2007

Flow characteristics of polymer solutions and crosslinked gels through porous media form the bases for several important enhanced oil recovery processes. When a polymer solution is injected into a reservoir for mobility control, flow distribution determines the flood efficiency. When Cr(III) crosslinking is applied to xanthan for profile modification, flow distribution of the gel solution along with gelation kinetics dictates gel placement and its effectiveness in improving subsequent water flooding.

Rheological characteristics of xanthan and xanthan/Cr(III) solutions are discussed in this paper. Flow rate ratios between capillary bundles of contrasting permeabilities were measured. Flow rate ratios of shear-thinning xanthan and xanthan/Cr(III) solutions were shown to be higher than those of water at low shear rates. Thus, biopolymer solutions are expected to preferentially enter high-permeability streaks in a reservoir formation. A theory to explain this selective emplacement characteristic has been formulated by combining a rheological model and Darcy’s law.
Improved Matrix, Fracture Fluid Transfer Function in Dual Porosity Models
Authors: Ishimoto K.
Published: December 2007

In the recent literature, much attention has been given to the simulation of naturally fractured reservoirs. The most prevalent approach is a dual-porosity formulation with computational blocks that may represent the system of fracture network by the noncontinuous matrix blocks. In models of this type, proper formulation of the matrix/fracture fluid transfer by gas/oil drainage and water/oil imbibition is requisite. The conventional description of this transfer function uses a matrix/fracture transmissibility and capillary and gravity gradients based upon the averaged values of matrix saturation assuming a simplified saturation distribution in the matrix, or is obtained by "history-matching" using a fine grid model of a single matrix block.

In this paper. the author presents a matrix/fracture transfer model which is consistent with the experimental data. Using vertical equilibrium to define the transition zone in the matrix blocks, the effects of the viscous, capillary and gravity forces on the fluid transfer between matrix and fracture are integrated. The fluid transfer calculated from this approach includes the effects of a varying Pc through the transition zone, the changing gravity potential with the relation between the segregated oil- water contact level in the fracture and the bottom level of the transition zone in the matrix, and the changing matrix block surface area which contributes to the fluid transfer. This approach has been successful in matching laboratory results of fractured systems that could not be matched by the conventional dual-porosity formulations.
An Assessment of Rate Sensitivity by Reservoir Simulation
Authors: Thomas G. W. , Breit V. S.
Published: December 2007

The effects of variations in production rate on ultimate recovery are presented for several different combinations of reservoir description and producing mechanisms. The results were obtained from reservoir simulation studies, and were intended to verify the intuitive concept that every reservoir has some limiting production rate, which, if exceeded, can result in serious losses in recoveries.

Our most sophisticated reservoir engineering tools, i.e. reservoir simulators, invariably indicate little rate sensitivity and frequently predict high ultimate recoveries at higher producing rates. In this paper, we focus on the reasons why this occurs when using standard off-the-shelf simulators that have not been equipped with special features to properly address the rate sensitivity issue. We then examine the factors that affect rate sensitivity, i.e. fingering, oil trapping, pore structure, variations in fluid properties, capillary hysteresis, etc., and concentrate on what a reservoir simulator requires to adequately treat these phenomena. We also demonstrate that when a simulator fulfills these requirements, rate sensitiviy is exhibited in certain instances.

Finally we present examples for water-oil, gas-oil, gas-gas and fractured reservoir systems.
A Perspective of Service Company Operations in China
Authors: Maier L. F.
Published: December 2007

The role of the modern international service company is reviewed and the current business framework within which such companies operate in China is described. Examples of technical service operations in Chinese oilfields are given. Service equipment sales and the co-manufacture of equipment are discussed. Recommendations are made for the expansion of future interaction and cooperation with Chinese organizations.
Applicability and Accuracy of Two Component Characterizations of Reservoir Oils for Numerical Modeling Purposes
Authors: Coats B. K. , Nolen J. S. , Sherman A. H.
Published: December 2007

The applicability and accuracy of a new binary pseudo-component PVT representation relative to conventional black-oil and equation-of-state representations is determined. This PVT representation extends the conventional black-oil treatment by decoupling the reservoir and surface PVT properties and. by modeling the properties of oil and gas through the use of K-values and Z-factors for a two component system.

Processes considered include depletion, water injection, and gas injection in oil reservoirs. In depletion simulations the ability of the two-component K-value (2CKV) representation to model gas phase condensation in surface separators results in higher and more accurate (relative to equation-of-state predictions) oil recovery predictions than those obtained using a conventional black-oil model. The capability of the 2CKV formulation to model time-dependent separator conditions is shown for a waterflood in a vertical cross section. Neither the 2CKV nor the black-oil formulation can accurately simulateds a gas injection process when the composition of the injection gas is significantly different from the composition of equilibrium reservoir gas in the injection cell(s).
The Evaluation of Drilling Fluid Filter Cake Properties and Their Influence on Fluid Loss
Authors: Arthur K. G. , Peden J. M.
Published: December 2007

Reported are the results of an experimental programme to investigate the influence of mud composition, pressure and temperature on the properties of filter cakes formed during static filtration. Three water-based muds were tested at pressures up to 4.2 MPa and temperatures up to 93°C. The spurt loss, cumulative fluid loss, cake thickness and porosity were measured and, using a modified static filtration equation, the cake resistance and compressibility were calculated.

The results clearly illustrate the highly compressible nature of filter cakes formed from drilling muds. Also shown is the profound influence of barite and temperature on the cake properties and fluid loss. Using expressions developed in the general field of solid-liquid separation for the variation in porosity within the filter cake, the behaviour of highly compressible cakes under pressure has been illustrated.
Mechanical Aspects of Medium Radius Well Design
Authors: Kerr D. , Lesley K.
Published: December 2007

General techniques for designing the bottomhole assembly (BHA) for a medium radius horizontal well are reviewed with emphasis on achieving an integrated drilling system by optimizing bottomhole assembly performance via the proper selection of BHA components. Systems analysis includes detailed mechanical modeling of the bottomhole assembly with concentration on minimizing torque and drag. Other design considerations include stress analysis of a reverse tapered drillstring with emphasis placed on design considerations to ensure the integrity of the entire drillstring. A case history will be discussed for a typical medium radius horizontal well.
Design and Operation of Two Remote Controlled Platforms in the Baltic Sea, West Germany
Authors: Klatt H. J. , Klumker H. C. , Siebel K. A.
Published: December 2007

The Schwedeneck-See oi1 field is the first offshore oilfield developed in German waters and so far the first field in the Baltic Sea (Fig. 1). A special design of offshore facilities for the pipeline and communication system had to be considered due to wheather impacts and strong requirements for environmental protection.-The paper describes reasons for the selection of concrete gravity type platforms, the construction and and installation of platform facilities in 15 - 25 m (50 - 80 ft) water depth, as well as the pipeline and remote control system.-The field is in operation since late 1984. Operation experience with the production and supervisory systems will be discussed.
Rheology of Waxy Crude Oils
Authors: Wardhaugh L. T. , Boger D. V. , Tonner S. P.
Published: December 2007

Crude oils from China, Australasia and many other parts of the world, containing waxy crystals and colloidal asphaltenes, possess distinct non-Newtonian flow properties which depend strongly on the shear and thermal history and result in special difficulties being encountered in all types of viscometers. Experimental techniques are discussed which allow reproducible equilibrium data to be obtained in the concentric cylinder and the cone and plate viscometers. The shear history dependence of the flow properties, which is shown to occur in both Australasian and Chinese crudes, alters the conventional design and scale-up assumptions. Flow in a capillary or pipeline is shown to be a composite effect of the range of shear rates that occurs across the radius of the pipe. An identical composite effect must occur for the scale-up assumption to remain valid. Pipeline flow can be determined from laboratory data by modified design techniques which also allow the quantitative assessment of oil treatment methods. A lower limit to pipeline operation, due to the shear history effect, is shown to exist, which has an effect on the assessment of oil treatment methods and on the operation of declining oil-fields.
An Ada-Based Software Development Environment as Applied to Completion and Production Operations
Authors: Ramamurthy G. , Ward V. L.
Published: December 2007

Simulation softwares currently used in the oil industry have generally suffered from a lack of maintainability that has often led to a periodic complete rewriting of the codes, resulting in inefficiencies in the software development cycle. Generally, these problems have their origin in either an absence of long-term specifications for the applications, a lack of adoption of software engineering principles to help upgrade the codes, or the involvement of various teams in the development of different phases of the product.

However, the advent of Ada is changing the software cycle with a number of features that permit a smooth evolution of the softwares; these features include the object-oriented development of modules, and both the reusability and a high level of data abstraction for the associated components. The modularity of the codes is enhanced by the hierarchy of the processes used. Communication between different development teams and protection of the code are handled by the information hiding process.

A series of Ada-based portable softwares has been developed using this methodology: their primary application is in fracturing and cementing; however, similar development strategies can be easily transposed to other applications. The main engine is a data structure handling system associated with different numerical and processing tools. The first system relates to the types of variables and their representation, while the latter consists of general tools for finite elements and finite difference discretization. Applications based on these concepts are described in detail.
Using Microcomputers as Reservoir Engineering Workstations
Authors: Blanc G. , Patey D.
Published: December 2007

The paper describes the software tools used to develop reservoir engineering software which are portable on a wide range of computers. These tools are: An APPLICATION LAUNCHER which hides the operating system commands to the user,A PROGRAM GENERATOR which is used to build all the screen based preprocessors,A library of graphic routines.

Two examples are given to illustrate the usefulness of such software on MS-DOS micro computers: The first one is a single well model simulator which features a medium sided reservoir engineering application. The resulting package includes a preprocessor, a postprocessor and the numerical model simulator itself.The second one is related to the full field simulation of petroleum reservoirs. For such a high end application the microcomputers can be used to do the preprocessing and postprocessing tasks. Furthermore the numerical simulation of the three phase, three dimensional model can be performed on the new generation of 32 bits microcomputers.

The two benchmarks which are presented show that the number crunching capabilities of microcomputers were considerably improved since the first IBM-PC was introduced. The last generation capabilities are close to those of minicomputers.
Successful Development of PC Engineering Applications
Authors: Schwager R. E. , Baldwin J. O. , Lochmann M. J. , George L. E.
Published: December 2007

Personal computers alone cannot change the effectiveness of energy professionals. This will be achieved only through the development and implementation of useful software tools. Software developers, either internal staffs or third party vendors, must establish strategies and standards which determine the design and function of the final product. The environment in which the software operates must be compatible with the philosophy of the developer, while simultaneously addressing all of the legitimate needs of the user community.
PS/2 and OS/2, and PC Workstation Futures
Authors: Hunt B. J.
Published: December 2007

IBM's introduction of the Personal System/2 (PS/2) personal computers and the Operating System/2 (OS/2) are part of an overall Systems Application Architecture (SAA) plan aimed at bringing all lines of computers from PCs to mainframes closer together. Since the benefits of IBM's proprietary PS/2 technology is presently unclear, the decision to purchase IBM's PS/2 or third-party "clones" should be based primarily on price versus performance. The introduction of OS/2 is a true performance breakthrough, but its benefits will not be seen until new applications are developed to take advantage of the new features.
Integrated Microcomputer Software for Petroleum Engineers: A Team Development Approach
Authors: Johnson J. B. , Woods N. O. , Smith D. E.
Published: December 2007

Using a team development approach, ARCO Oil and Gas Company has developed an integrated microcomputer database system for petroleum engineers. This system provides a framework for compact storage, retrieval, and interchange of data between various technical applications. It also gives the engineer an ability to manage all common oilfield data for input, analysis, and reporting. High resolution graphics, "help" screens, and consistent user interface standards allow the engineer to readily utilize the capabilities of the petroleum engineering applications with very little manipulation of input data. This paper describes the management process used in development of the system and discusses several of the major considerations critical to the system's design.

In an effort to bridge the gap between computer science and petroleum engineering technologies, a specific software development team was created consisting of ARCO petroleum engineers, ARCO computer scientists, and consultants from the microcomputer software industry. This team approach to software development allowed the implementation of petroleum engineering technology with appropriate consideration of available computer possibilities. The team was headed by a petroleum engineer who defined the capabilities desired of the software, while the computer specialists on the team provided dynamic feedback and suggestions for ways to accommodate the petroleum engineering tasks on a microcomputer.

Much consideration was given to meeting computer industry standards and leaving options open for future expansions. Questions regarding mainframe links, networking, compatibilities with other computer systems, and future hardware/software developments were ever present in design of the ARCO system. More importantly, the system had to work efficiently with today's hardware and be developed at a minimum cost. The completed software system is a direct result of synergistic input from team members and provides a workable framework for development of future petroleum engineering microcomputer software.
Linear Programming Optimization on Microcomputers
Authors: Brown D. L. , Wattenbarger R. A. , Startzman R. A.
Published: December 2007

A common type of mathematical optimization is Linear Programming (LP). An LP solution of aquifer influence functions has recently been reported by Gadjica, etal.1 (1987) and Targac, etal.2 Their LP matrices were large and sparse (only 3% of the elements were non-zero) and were solved on main frame computers. Another recent application of LP is equation-of-state matching of laboratory PVT data3. This problem leads to a smaller, denser LP matrix.

Three methods of LP solution were investigated on microcomputers: (1) the simplex method, (2) the revised simplex method, and (3) the symmetric method. These methods were run on several LP problems ranging from a small dense matrix to large sparse matrices. The different methods have different characteristics which affect the speed, storage requirements and simplicity of coding. The simplex method is straightforward, but usually is slower and requires more storage than the other methods.

The results of this study are tabulated with running times and storage requirements for the various LP methods and microcomputers. The computers range from the IBM XT to the Compaq 386. This information serves as a documentation of the LP codes and should be useful for an engineer interested in using LP codes on a microcomputer.
Developing an Effective Microcomputer User Support Strategy in the Petroleum Industry
Authors: Engler R. A.
Published: December 2007

In recent years, the proliferation of large numbers of microcomputers has greatly changed the requirements for user support. Companies which have historically had strong centralized mainframe computer staffs are now required to support users in ways which were not necessary in the past. In mainframe systems, user support is usually limited to help in running programs and occasional hardware repairs. As microcomputers have spread throughout the workplace, support must now be expanded to include software and hardware distribution and installation, as well as training for a greatly expanded user community. The petroleum industry is a unique case in the user support problem, particularly for exploration and production companies. The normal support problems are complicated by the need to put computing assets in remote locations, often with hostile environments. The user community will often span a wide range of educational experience and computer experience. This paper discusses several concepts involved in developing a microcomputer user support strategy in the petroleum industry.
A Framework for the Selection and Implementation of PC Software and Its Effects on Productivity
Authors: Baldwin J. O. , Schwager R. E. , Lochmann M. J.
Published: December 2007

One of the primary justifications for the use of personal computers is increased productivity, to be obtained through the achievement of specific goals. The process of selecting and implementing PC software applications has a direct impact on achieving productivity gains, therefore goals must be kept clearly in mind throughout any evaluation. In order to achieve success, the goals set for productivity must be straightforward, concise and reasonable, or the process will attain only limited success, or could fail altogether. This paper outlines how a selection/implementation committee can bring order to this chaotic process.
Measurement-While-Drilling Mud Pulse Detection Process: An Investigation of Matched Filter Responses to Simulated and Real Mud Pressure Pulses
Authors: Marsh J. L. , Fraser E. C. , Holt A. L.
Published: December 2007

A study was performed for the purpose of evaluating various methods of signal (MWD mud pulse) detection in the presence of simulated and real noise. The performance of rectangular and double exponential matched filter correlators was determined using simulated pulses in the presence of band limited gaussian noise and coherent noise. Actual field recordings of MWD pressure signals were then digitized and passed through the correlation process to determine the relative merit of various correlation schemes. Samples of recordings for both easy detection and difficult detection drilling situations were used for this evaluation.

The results of this study show that the correlation detection process is a remarkably robust method of detection of MWD mud pressure signals in real and simulated noise. They also point out the relative insensitivity of the correlation detection process to variations in the shape of the replica of the pulse used in the matched filter.
EOR Screening With an Expert System
Authors: Guerillot D. R.
Published: December 2007

The application of an Artificial Intelligence (AI) technique to assist in the selection of an Enhanced Oil Recovery process (EOR) is described. The aim of this Expert System (ES) is to provide reasoned comments on the applicability of such processes on the basis of reservoir characteristics.

The knowledge base has been developed using a professional inference engine. To be closer to the type of reasoning used by experts, fuzzy logic concepts have been introduced in the knowledge representation.

This approach leads to a methodology for selecting EOR processes and for improving know-how by checking the criteria used by comparison with practical experience, and it helps to transfer the expert's knowledge to the users of the system. Moreover, estimations of additional field cases makes it possible to continuously refine the screening procedure.
Optimization of Well Stimulation Strategies in Oil and Gas Fields
Authors: Sinson C. M. , Ogbe D. O. , Dehghani K.
Published: December 2007

Optimization methods of linear and non-linear programming have been used in the oil industry to study the scheduling of oil well production and drilling, and to determine the optimal investment policies.

There are few studies published in the area of optimization of well stimulation policies. This paper describes the application of non-linear mathematical programming methods to optimize the design and evaluation of oil and gas wells for stimulation.

The model presented is modular and it has three sub modules: SCREEN, DESIGN, and OPTIMIZE. The screening module combines pre-stimulation production performance data, geological and reservoir data to match a well to one of four stimulation operations, namely, hydraulic fracturing, matrix acidizing, acid fracturing and recompletion. In the second module, the design of the stimulation operation selected from the screening module is performed. The program uses widely - accepted equations and correlations to design hydraulic fracturing, matrix acidizing, acid-fracturing and recompletion. In the optimization module, analytical decline curve and economic discounting techniques are used to predict the production profile after the stimulation operation, and to determine the time value of money and production. The optimization model combines the reservoir and economic data to determine the optimal well stimulation strategy.

The constraints of the optimization model, include those imposed by the reservoir, the production facilities, operating costs, and operating budget of the field. Program development and validation procedures, and the application to field data are presented in the paper.
A Multiple Purpose Application for the Solution of Petroleum Industry Problems Using Microcomputers
Authors: Whitney J. A.
Published: December 2007

Apple Computer, Inc.'s software package, HyperCard™, which runs on Macintosh™ microcomputers, is a multiple purpose "application" that can be used for the solution of petroleum industry problems. These problems can encompass not only the engineering area, but also other tasks that occur in the industry.
Vertical Expansion Program Monitoring: Technical and Design Considerations of PC Data Collection Used With Mainframe Plot and Report Capabilities
Authors: Young A. T.
Published: December 2007

The use of a mainframe-based application with a PC-based data capture "front end" is discussed as a viable production analysis tool utilizing the large volume of data now available on two Chevron U.S.A. fields with wells completed in multiple zones. The technical and design considerations encountered during the development of this application can be applied to a variety of petroleum industry data processing problems where data capture is desired from remote or non-company sources.

This application was designed to make effective use of available manpower as well as the company's extensive mainframe resources for generating the desired reports and plots. These issues are discussed, as they relate to the application's design objectives and expected performance.

As of the manuscript date, much of this application is still under development. Evaluation of the design chosen will necessarily continue through development into the application's productive use.
Trials and Tribulations of Installing a Local-Area Network
Authors: Merchant M. A. , Zamora M.
Published: December 2007

For many, the advent of the Local-Area Network (LAN) has brought with it the promise of improved productivity, shared peripherals, common databases, distributed processing, simplified software distribution, better communications, instant access to computer resources - all at rock-bottom prices and from inception to implementation in a matter of months or even weeks. No doubt these expectations can be satisfied, but it certainly is not as easy and straight-forward as some vendors and computer gurus would have us believe. We know.

We installed a LAN to replace a superminicomputer, time-sharing system used primarily for engineering, word-processing and telecommunications. The project was successful, yes, but not without a host of trials and tribulations.
Study on Pore Structure for Waterflooding Sandstone Reservoir in Xinlongtai Oil Field
Authors: Yulong Wang , Zhongren Niu
Published: December 2007

For the purpose of improving water flooding development after a high - water-cut period, a classification of reservoir pore structures is presented in this paper based on the practice of Xinglongtai Oil field. Meanwhile. the relationship among depositional facies. diagenesis and pore structure is discussed. The pore structure is closely linked with depositional facies and petrophysics, showing the characteristics of getting worse m uniformity of pore throats along with improving rock properties as the effect of depositional conditions and diagenesis. Pore structure is critical to the vertical and horizontal water washing efficiency. Thus- the study on pore structures would be an important subject in improving water washing efficiency and mobilizing the remaining oil potential of pay zones during the middle and late periods of development.
Some Techniques For Outlining The Size Of Oil (Gas) Reservoirs In Evaluation Stage
Authors: Zhang Zhisong
Published: December 2007

Early identification of reservoir size can be made by a minimum number of exploratory and appraisal wells. A differential analysis method is described where logging data are used to distinguish the oil, gas and water bearing zones in the stages of exploration and early evaluation. Examples are also given to illustrate the use of stratigraphic correlation and regional fluid pressure analysis for this purpose.
Cluster Drilling Technology in Damintun Oil Field
Authors: Zhiying Ouyang , Suru Lu
Published: December 2007

The cluster drilling technology, as an important part of development and construction of Damintun high pour point oilfield, plays a significant role. It has overcome various difficulties caused by around conditions, reduced ground area used in oilfield, simplified the construction or the facilities, cut down the \ill\ of heat and electrical energy, reduced total investment for oilfield construction. Therefore, it accelerated ihe oilfield construction greatly.

A complete set of drilling techniques used in this oilfield are advanced in te-chnology, successful in operation, and a pioneer for developing high pour point oil fields in China. First, it solved various problems in general planning and design or development of fault multiple resèrvoires with cluster drilling firstly in China. At the same time, it obtained a significant benefit. For example, 17 wells were drilled on No. 10 pad in Damintun Oilfield: one vertical well and sixteen directional wells. By comparison with B platform of Chengbei Oilfield in Bohai drilled by Japan Drilling Company (JDC) in 1984, the technical level in design and well path control is nearly the same. Its success shows that we have had the ability to drill concentrated wells on pad with our own techniques. Second, new techniques such us new drilling fluid of high quality, low density slurry, proper well program, near-balance pressure drilling, optimizing parameters and, high pressure jet drilling, prevention and disposal of drilling troubles, detection control and data processing are comprehensively used in drilling, and a complete set of cluster drilling technology for producing high pour point oil and preventing formation damage in Damintun Oilfield are developed.
Directional Drilling Technology with the Parabola Method
Authors: Weian Gong
Published: December 2007

This paper describes the general theory and method of calculating drag force while tripping in directional wells. The application of the theory has demonstrated that the drag force created in the quadratic parabola trajectory while tripping is smaller than that of the catenary path no matter whether the dead weight of drill string is considered or not. Based on the analysis of the approximation of catenary equation, the changeability and uncontroliability of the downhole horizontal tension, and randomness of the design, it is believed that the theoretical trajectory of catenary path does not coincide with the actual drill string catenary trajectory in a well, and thus the expected results can not be obtained. The degree of difficulty in drilling, completion, production and some other downhole operations is compared between the two trajectories. It is concluded that the directional wells with quadratic parabola trajectory offer more advantages than those with catenary path.
Sand Control Technology with Plastic Pre-Coated Sand Grain
Authors: Chengqui Fan
Published: December 2007

Sand control with plastic pre-coated sand is an important improvement of the technology of chemical sand control. Gravel particles are covered with half cured Phenolic resin to prevent adhering of shaped particles. On the well site, the free flowing particules are transported by sand carrying fluid to the formation to be treated-Under the action of the formation temperature, the particles covered with resin can be bonded by themselves to form a barrier during oil production. The plastic pre-coated sand presently used is only suitable for formation temperature above 60 °C. For the oil wells with formation temperature below 60 °C, the curing time is longer and the bond strength is smaller. The field test in Dagang oilfield of China shows that not only the problems encountered during previous chemical sand control operation can be solved, but also the success rate is improved. For the wells tested, the oil production is generally restored, and less sand flushing is required, making continuous and normal production of the oil wells possible.
Application and Development of Profile Modification Techniques in Water Injection Wells
Authors: Yuxiang Li
Published: December 2007

In a multilayer heterogeneous oil reservoir developed and exploited by water flooding, most of the remanant oil is distributed in the unflushed part of the developed reservoir. Improvement of the conformance factor and the displacement efficiency should be the main EOR technique. Profile modification in an injection well is an effective technique in the improvement of the volumetric sweep efficiency of the water flooding.

This paper gives a summary of the application of the profile modification technique in the injection wells in Chinese oil fields and its further development. Some examples on the effectiveness of this technique are presented and analyzed.
Unconventional Well Control Techniques
Authors: Junfang Hao , Kai Liu
Published: December 2007

Complicated well control problems could be divided into two categories: the conventional well control method in which the bottom hole pressure can always be kept equal to the formation pressure during the killing operations and \ill\ the unconventional method in which the pressure can not be in equilibrium with the formation pressure. Three kinds of unconventional well control methods: low choke pressure method, killing an empty well and killing a blowout well are discussed in this paper. The formation, borehole and wellhead are considered as a communicating system, in which the three are influenced and restrained by each other. Based on reservoir gas filtration mechanism in steady and unsteady states, the basic principles of unconventional well control have been studied, and the related mathematical models and calculating methods have been established. The calculation results, have been compared and checked with laboratory experiments and field data(1).
A Standardized Method Of Monitoring Water Quality In Sub-Surface Injection Systems
Authors: Bilhartz Harrell L.
Published: December 2007

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

A method of programmed data acquisition is presented to help non-specialist engineers monitor water quality. Field tests, sample collection, laboratory procedures and methods of data presentation are standardized. Specifically, a series of profile plots are prepared from which engineers "read-out" pertinent features of plant performance and water quality. The direct "read-out" procedure, after nominal practice, is relatively simple. In many respects, it may be compared with qualitative log interpretation.

A manual for using the Standard Data Package is also presented. Included are "rules of thumb" and other empirically derived "yardsticks" covering several important parameters.

Introduction

The increasing importance of salt water handling, either in disposal or waterflood operations, has demanded development of better methods. A full understanding of basic parameters is fundamental to creating the best plant design and to determining the most effective operating practices. Toward this end various methods have been proposed to define "water quality", diagnose problems, predict potential problems and ultimately, to use these technical method to maximize operating efficiency.

It is a major purpose of this paper to present a standardized method of programmed data acquisition that lends itself to direct measurement of water quality by non-specialist engineers. The heart of the program is the collection and preparation of a "Standard Data Package". While involving a comprehensive technical investigation, the interpretation process is simplified so that unusual technical skills are not often required.

Specifically, a standardized format is proposed whereby engineers can inspect a series of charts and "read-out" pertinent features of an injection system's performance. While the "read-out" process appears quite simple, the individual is in effect solving partial chemical material balance calculations that logically lead to sound engineering conclusions.

The standardized plan is readily adaptable to regular surveillance of water systems. After an initial comprehensive study, data acquisition can be programmed in advance so that attention is focused on an operation at regular intervals. Comparison of standard charts of succeeding studies is done by inspection. Likewise, with all procedures standardized, results between studies of different projects can be directly compared.

BASIC CONCEPT

The proposed plan of water quality control can be illustrated by noting the physical similarity of water injection systems and chemical manufacturing plants. Both convert raw material to finished products. Either may be simple or highly complex. Systematic collection of basic in-put and out-put data is recognized as a requirement for efficient operation of a manufacturing plant.
High-Temperature, High-Pressure Rheology of Water-Based Muds
Authors: Alderman N. J. , Gavignet A. , Guillot D. , Maitland G. C.
Published: December 2007

This paper reports measurements of the rheology of a range of water-based drilling muds at temperatures up to 130°C and pressures up to 1000 bar. The fluids are highly thixotropic; decoupling of temperature/pressure effects from those due to time-dependent structural changes was achieved by developing a sample preparation and handling procedure which ensures that all samples experience identical shear histories prior to study in the rheometer. This enabled essentially equilibrium flow curves to be determined over a shear rate range of 0 – 1200 s−1 with a reproducibility of better than ±1 Pa in stress.

The data were best fitted using a three parameter Herschel-Bulkley yield/power-law model although in many cases, particularly at low temperatures and high pressures, the two parameter Casson equation gave an acceptable fit for engineering purposes. For both models the behaviour of the high-shear viscosity reflected the viscous behaviour of the continuous phase: a weak pressure dependence and an exponential temperature dependence matching that of water. The pressure dependence increased with mud density. In all cases the fluid yield stress was essentially independent of pressure. In contrast to oil-based muds, where this quantity decreases with temperature, for these water-based systems it remained constant below some characteristic temperature, whereafter it increased exponentially with inverse temperature.

The physical origins of the observed behaviour are discussed and a simple model for representing the data is given. It is shown how this may be used for reliable extrapolation of surface measurements to downhole conditions for well-circulated water-based muds.
Dynamic Filtration of Bentonite Muds Under Different Flow Conditions
Authors: Fordham E. J. , Ladva H. K. J. , Hall C. , Baret J-F. , Sherwood J. D.
Published: December 2007

The variation of key parameters describing the dynamic fluid loss behaviour of two water-based drilling muds, barite-weighted and unweighted, has been systematically investigated in an annular flow dynamic filtration cell designed to provide well-controlled laminar flows over a wall shear rate typical of those in the wellbore during drilling.

An axial section of the cell inner wall is formed from a 10 millidarcy ceramic filter. The permeability and low particle penetration decouples the cake filtration from formation invasion or formation damage effects. A variable annulus gap was designed to reveal possible Reynolds number effects as well as the dominant wall shear rate effects.

Numerous dynamic fluid loss histories at a filtration pressure of 280 p.s.i. (1.93 MPa) (typical duration 22 hours) show that the fluid loss can be described by three key parameters: one describing the early (‘quasi-static’) behaviour, a second describing the late (‘dynamic’) behaviour of near-constant fluid loss rate, and thirdly a timescale for the transition between these two regimes.

The variation of these parameters with mud flow wall shear rates between 50 and 650 s−1 has been quantified empirically. The early behaviour is virtually independent of shear, but the timescale for transition to ‘dynamic’ behaviour decreases sharply with increasing shear rate from 5 hours to about 14 hour. The final ‘dynamic’ fluid loss rate correlates approximately with the 0.6 power of the shear rate; other theoretically postulated variations are not supported. The irreversible deposition of mudcake under dynamic conditions reported by others has also been observed.

The results have direct application to the modelling of fluid loss in drilling and in well completions. The quantitative laws obtained have also enabled some discrimination to be made between theoretical models for the fundamental mechanisms of mud particle deposition and erosion.
Environmental Impact of Ocean Dumping of Drilling Muds and Cuttings in San Pedro Basin, Offshore California
Authors: Otott G. E. , Mikel T. K.
Published: December 2007

From July 1985 to August 1986 Thums Long Beach Company disposed of waste drilling muds and cuttings in San Pedro Basin of the Southern California offshore area. Higher costs for onshore disposal had made ocean disposal economical during a multi-well drilling program. Ocean dumping was discontinued due to a decline in drilling activity.

Ocean dumping was conducted according to conditions of a U.S. Environmental Protection Agency (EPA) Ocean Dumping Permit for disposal of specific types and amounts of drilling muds and cuttings. A dumpsite specifically for muds and cuttings was designated by the EPA and is located 16 miles from Long Beach Harbor in water depth of 3000 feet. The disposed material consisted of water-based drilling mud and formation cuttings. The drilling mud was similar to Generic Mud #7, one of eight generic muds established by EPA for use in the National Pollutant Discharge Elimination System permit program. The cuttings were from unconsolidated sandstone and shale formations. Disposal of muds and cuttings was via a specially designed barge that can hold up to 6000 barrels of waste material. The muds and cuttings were blended together when loaded onto the barge and the, slurry was pumped overboard through a hose that extended below the water surface.

Ocean monitoring was conducted at the dumpsite during the three year permit period. Ocean monitoring included seafloor sampling and testing, water sampling from surface to 3000 feet, continuous water column profiling, and field verification of the discharge plume model. Results of the water quality and benthic monitoring program show that ocean dumping operations conducted by Thums in San Pedro Basin appear to have had no significant impact on the marine environment. Results of the discharge plume verification study show that the plume was rapidly dissociated and diluted below detection limits.