bluuebunny/crossref_metadata_2025_split huggingface dataset:
Organization of Field Tests and Evaluation Of Tricone Bit Performance Using Statistical Analysis and Sonic Logs
Authors: Raynal Jean C. , Gstalder Serge A. , Sagot Andre M. , Muckleroy J.A. 
Published: December 2007

Raynal, Jean C., SPE-AIME, Societe Nationals des Petroles d'Aquitaine Gstalder, Serge A., Societe Nationale des Petroles d'Aquitaine Sagot, Andre M., Societe Nationale des Petroles d'Aquitaine Muckleroy, J.A.,* Amoco Production Co.
The scatter of data in oilfield drilling makes evaluation of results using different bits highly uncertain. Conventional statistical theory is here applied to samples of field results to clarify and quantify evaluation, and recommendations are presented for organizing drillsite tests.

Introduction
The original text of this paper, which far exceeded the SPE's allowable length, has been condensed by the translator, using American statistical terms and drilling nomenclature. The complete original English text is on file with the SPE. For space reasons, it was necessary to omit the extensive mathematical and statistical development of the original; instead, references are given to standard textbooks where the basis of this development may be found. Although the statistical approach discussed here has been widely employed in agriculture, medicine, pharmacology, chemical analysis, pilot plant operation, and other fields in which tests are made on samples of a product or on changes produced by a cause, this approach of making statistical tests on pairs of experimental results on bits seems to have been largely neglected in drilling.

Statement of the Problem Definition of the Problem
When in drilling a well a technique or a tool is changed, it is often very difficult afterwards to answer the essential question: Did the change improve the result, or make it worse? Drilling results may be essentially shown in three ways:as footage drilled per hour;as footage drilled per bit; andas the cost per foot drilled, which incorporates the preceding two and is the most important result.
The difficulties in judging these results are many and varied, but they always manifest themselves in a loss of time and so of money. If we wish the drilling tests to be proved absolutely, they must be repeated many times; if, on the other hand, we jump to a hasty conclusion, the result can be a bad decision. Either route is costly.

Analysis of the Problem
There are many variables in drilling, of which the most important are the following:
Weight on bit (W) Diameter of bit (D) Type of bitWear on bit when pulled Revolutions per minute (rpm) Flow rate of drilling fluid (Q) Nature and properties of drilling fluid Pressure difference across rock surface ( p) Depth Rock properties
Most of these are poorly measured. For the same drilling rig, drilling the same well, it is relatively easy to maintain constant values of W, rpm, and Q.
JPT
P. 506
Coiled Tubing as Initial Production Tubing: An Overview of Case Histories
Authors: Nirider H.L. , Snider P.M. , Walsh K.D. , Cordera J.R. , Williams Joe 
Published: December 2007

Summary
From Jan. 1993 through Feb. 1995 Marathon Oil Co. completed 23 newly drilled gas wells with coiled tubing as the initial production string. This paper reviews operational aspects of representative jobs, summarizes areas where improvements in equipment and technique were implemented, and addresses cost and productivity benefits of rigless completions. A summary of lessons learned is also included.

Introduction
Marathon has used coiled tubing for initial production tubing in several wells to match the tubing to the well productivity, to unload fracture fluids as quickly as possible, and to minimize cost by reducing the time the drilling rig stays on location. Use of coiled tubing allows tubing size to be matched closely to the performance of relatively low rate wells, minimizing the tubular costs and improving the well's ability to stay unloaded. In areas with water-sensitive formations, live-well completion prevents formation damage associated with kill fluids.
The main areas of improvement from one job to the next involved the use of a pressurized, hydraulically operated access window, ensuring that all fracture sand was cleaned out before landing the coiled tubing and using a "hot-cutoff' system to make the final cut on the coil tubing. An additional benefit is that no fluid is lost to the formation during the completion.
Lessons learned include keeping the coiled-tubing size large enough to run smaller coiled tubing through it for cleanout and slickline work, care in closing blowout preventer (BOP) rams to avoid damaging the coiled tubing, and the use of wellhead equipment specifically designed for use with coiled tubing. This technique is especially suited to low pressure and water-sensitive reservoirs where fluid loss is a concern. An additional benefit is the cost savings from reducing the hole and casing sizes to match the reservoir potential. In addition, this completion technique is often quicker than using a conventional completion rig and jointed tubing.
An Evaluation of Concentric Casing for Nonuniform Load Applications
Authors: Pattillo P. D. , Moschovidis Z. A. , Lai Manohar 
Published: December 2007

Summary
This study offers both theoretical and experimental evidence of the benefits of running a concentric casing configuration in a nonuniform load environment. The study is further enhanced by numerical modeling, particularly with regard to determining the sensitivity of the configuration to key variables. The alternative of running a single string of heavy-wall casing also is discussed.
Integrated Management Of Multiple Reservoir Field Developments
Authors: Lyons S.L. , Chan H.M. , Harper J.L. , Boyett B.A. , Dowson P.R. , Bette S. 
Published: December 2007

Summary
This paper describes the coupling of a pipeline network model to a reservoir simulator and its application to optimize the production strategy of two Mobil field developments. Mobil's PEGASUS simulator is an integrated, all-purpose reservoir simulator that handles black-oil, compositional, faulted, and naturally fractured reservoirs. We have extended the simulator to allow simultaneous modeling of multiple reservoirs coupled with surface pipeline networks and processes. This allows us to account for the effects of geology, well placement, and surface production facilities on well deliverability in a fully integrated fashion. We have also developed a gas-contract allocation system that takes the user-specified constraints, target rates, and swing factors and automatically assigns rates to the individual wells of each reservoir. This algorithm calculates the overall deliverability and automatically reduces the user-specified target rates to meet the deliverability constraints. The algorithm and solution technique are described.
This enhanced simulator has been applied to model a Mobil field development in the Southern gas basin offshore the U.K., which consists of three separate gas reservoirs connected by means of a pipeline network. The simulator allowed us to determine accurately the effect of varying the development timing of these reservoirs on individual reservoir and total field performance. Several development scenarios are shown to illustrate the capabilities of PEGASUS.
Another application of this technology is in our field developments in North Sumatra, Indonesia. Here the objective is to optimize the development of multiple fields economically to feed the P.T. Arun liquid natural gas (LNG) facility. A range of gas compositions, well productivities, and facilities constraints are considered in an integrated fashion, resulting in improved management of these assets. Model specifics are discussed.

Introduction
Optimal exploitation of oil and gas fields requires an integrated approach. Several reservoirs in a field development typically compete for limited surface production capacity. Typically, as fields mature, the development of additional satellite reservoirs increases the competition for capacity in the surface facilities. This is especially true in expensive offshore projects. Historically, engineers have used reservoir simulators to develop an exploitation scheme for a given hydrocarbon reservoir. This approach optimizes the development of a single reservoir but neglects the total effect on surface-capacity limits from other reservoirs sharing the same surface facilities.
Plugging Off Water in Fractured Formations
Authors: Howard George C. , Scott P.P. 
Published: December 2007

Abstract
A field remedial procedure utilizing a kerosene-cement slurry as a water plug-off agent in fractured formations was evaluated both in the laboratory and in the field. This procedure has proved to be capable of effectively shutting off water without causing permanent impairment of the oil production. Success was attributed to the fact that an immobile cement slurry, when placed in a water-producing strata, will set and form an impermeable barrier; whereas when placed in an oil-producing section the cement will retain a relatively high permeability and may be removed by acidizing.

Introduction
One of the most perplexing problems facing the oil industry is the selective exclusion of water production from oil or gas-producing wells. This problem has been studied by many investigators in an attempt to develop a material that is not only capable of reducing water production but is also capable of being selective in that it will not impair oil production in either fractured or intergranular type reservoirs. A study of these two types of formations indicated that two distinct types of materials for controlling water production might be required - a completely liquid plugging agent for intergranular formations and a semi-liquid or slurry type plugging agent for fractured formations. This paper is limited to the control of water production from fractured formations.
A common source of water in the vicinity of oil bearing rock reservoirs is water which previously has entered and, because of its higher density, generally lies near the bottom of the formation. When the deepest point of penetration of a well into such an oil and water-bearing formation is above the level of the water, and the dynamical gradients due to the flow of oil overbalance the difference in densities between oil and water, water production becomes a problem. Then the water level rises in the shape of a cone and is produced from the lower depths.
Technology Transfer Through Integrated Production-Engineering Software
Authors: Zhu Ding , Wu Gary , Hill A. D. , Economides M. J. 
Published: December 2007

Summary
Just as the hand-held calculator revolutionized the capabilities of engineers 20 years ago, the desk top computer is revolutionizing technology transfer in engineering practice today. For example, more than 10,000 independent oil/gas producers in the U.S., most of whom have difficulty gaining access to the most updated technology, rely on personal computers (PC's) to keep up with the explosion of information and engineering-process developments.
Sensitivity Analysis Applied to a Steady-State Model of Natural Gas Transportation Systems
Authors: Stoner Michael A. 
Published: December 2007

Abstract
A nodal formulation for the mathematical model of a gas transportation system is presented and the Newton-Raphson method is proposed as a means of solving the resulting nonlinear equations. Once a solution has been obtained, a linearized form of the model can be used to assess the sensitivity or interaction of system variables. The equations necessary to perform this sensitivity analysis are developed and demonstrated on a sample system. A scheme for performing Gaussian elimination on a general set of simultaneous linear equations having a sparse coefficient matrix is presented.

Introduction
This paper espouses the use of a nodal formulation for the steady-state model of a gas transportation system and attempts to show how sensitivity analysis applied to this model can be used to aid in the design and operation of the prototype systems. the mathematical model used here has been described in a previous paper, which was based on earlier work. The basic model is recapped here. Solutions of this model are obtained using the n-dimensional Newton-Raphson (N-R) technique with an acceleration scheme, the main purpose of which is to prohibit divergence. The N-R method requires the solution of a set of simultaneous linear equations whose coefficient matrix for this application is very sparse. In preparing digital computer programs using this model, this sparsity has been exploited to great advantage in core storage savings and execution time efficiency. The basic aspects of a sparse matrix solution scheme for a general set of simultaneous linear equations and rudimentary programming steps are covered in the Appendix.
Once a solution has been obtained for the model, the user often poses questions such as, "How different would the solution be if I had specified a different value for this load?" Or "How much more horsepower would be needed here if we had increased this pressure 15 psi? The user could make the specified changes and resolve his model to obtain the answers. However, if he is willing to accept approximate answers to these questions, then an appropriately executed sensitivity analysis can provide the answers with considerable saving in computer time and associated expense. The development of the equations necessary to perform a general sensitivity analysis using the proposed model is presented. Computational shortcuts using the sparse matrix solution of a set of simultaneous linear equations are demonstrated. Finally, an example is hypothesized to demonstrate one way of using the proposed sensitivity analysis scheme.
Extending Rod-Pump Life During Proppant Flowback at the Lost Hills Field
Authors: Roberts I. G. 
Published: December 2007

Summary
Proppant flowback from hydraulically fractured wells can lead to sand wear on the pump barrel and plunger and to increased pulling costs on rod-pumped wells. Two separate approaches for lengthening the run times of the pumps were tried and evaluated individually. One approach was to install pumps that allow production of a sand-laden fluid. Pressure-actuated plunger (PAP) pumps were field tested, and they showed an average increase of 81.6% in run time. These split ring wiper pumps clean the barrel of sand before the passing of the plunger. The other approach was to keep the sand from entering the pumps. When downhole filters were used, the run life of the pumps with the filters increases 135%. Well-pulling cost savings of U.S. $11.91 per well day and U.S. $9.24 per well day are documented for the PAP pumps and filters, respectively. Application guidelines based on the sand-loading rate and gross liquid production of the wells are presented, as well as some operational experiences.
Development of the HT-BP Neural Network System for the Identification of a Well-Test Interpretation Model
Authors: Sung Wonmo , Yoo Inhang , Ra Seunghoon , Park Heungjun 
Published: December 2007

Summary
The back propagation (BP) neural network approach has been the subject of recent focus because it can identify models for incomplete or distorted data without performing data preparation procedures. However, this approach uses only partial sets of data to reduce computing time and memory, and it may miss the points representing characteristics of the curve shape. Therefore, the resulted model may not be correct, forcing one to use sequential neural nets to find the correct model.
We present the Hough Transform (HT) method combined with the BP neural network to improve this problem. With the aid of an HT, we can extract one simple pattern, including noisy and extraneous points, from the full-set data. A number of exercises also have been conducted for the published well-test data with the artificial intelligence neural network identification system (ANNIS) we developed. The results show that ANNIS is quite reliable, especially for the incomplete or distorted data. They also demonstrate that the modified Levenberg-Marquart interpretation model, also developed in this work, successfully estimates reservoir parameters.
Time Delayed and Low-impairment Fluid-loss Control using a Succinoglycan Biopolymer with an Internal Acid Breaker
Authors: Bouts Marcel N. , Trompert Ruud A. , Samuel Alan J. 
Published: December 2007

Abstract
The formation damage that results from the incomplete back-production of viscous, fluid-loss control pills can be minimised if a slow acting internal breaker is employed. In particular, core-flow tests have indicated that combining a succinoglycan-based pill with a hydrochloric acid internal breaker enables a fluid-loss system with sustained control followed by delayed breakback and creates only low levels of impairment To describe the delayed breaking of the succinoglycan/hydrochloric acid system, a model, based on bond breaking rate, has been used. With this model, it is possible to predict the change of the rheological properties of the polymer as a function of time for various formation temperatures, transition temperatures of the succinoglycan and acid concentrations. Hence, the model can be used to identify optimum formulations of succinoglycan and acid breaker on the basis of field requirements, such as the time interval over which fluid-loss control is needed, the overbalance a pill should be able to withstand and the brine density required.
Hydrofluoric Acid Reaction with a Porous Sandstone
Authors: Williams B.B. , Whiteley M.E. 
Published: December 2007

Abstract
A procedure is developed for predicting changes in the porosity distribution in a sandstone resulting from reaction with hydrofluoric acid. This procedure is based on a theory for slow heterogeneous reactions in a porous solid where the solid matrix is consumed in the reaction Process. Reaction-rate data for use in this theory are obtained from experiments where acid is injected through short cores and effluent concentration measured using a fluoride specific ion electrode. This rate is found to be first order in hydrofluoric acid concentration. Variations in rate with temperature and quantity of rock dissolved are shown.

Introduction
Mixtures of hydrofluoric and hydrochloric acid are used to stimulate gas and oil production from sandstone reservoirs by increasing formation porosity and permeability near the wellbore. This porosity and permeability near the wellbore. This acid will react with almost all constituents of naturally occurring sandstones, such as silica, feldspar, clays, and calcareous material. In order to utilize this acid effectively, it is necessary to predict where acid reacts and changes that occur predict where acid reacts and changes that occur with reaction.
Chemical reactions between hydrofluoric acid and silica or calcite in the rock matrix are simple, well known reactions. However, reactions with silicates such as clays or feldspars are complex since these minerals occur as three-dimensional lattices with only average empirical formulas. Examples are kaolinite ([A Fe +3 Mg]-Si O1.8 0.1 0.1 2 5 [OH]. Ca), montmorillonite (A Mg Si4 0.05 1.67 0.33 4 O [OH] . NA), and feldspars such as albite10 2 0.33 ([NaSi A ]). In the reactions shown below the3 8 reaction of sodium silicate is used to represent hydrofluoric acid reaction with silicates found in the matrix.
Waterflood Geochemical Modeling and a Prudhoe Bay Zone 4 Case Study
Authors: Li Ying-Hsiao , Crane Steven D. , Scott E. Mark , Braden John C. , Lelland W. Greg Mc 
Published: December 2007

Abstract
Scale formation during waterfloods can damage reservoirs far beyond the wellbore region. A comprehensive analysis with geochemical modeling can improve waterflood design in the selection and/or mixing of source waters and thus, mitigate formation damage arising from injecting incompatible fluids. The method also predict the types of scales and their severity at various production stages. This will help optimize treatment schedules and reduce operation costs.
In the case study of Zone 4, Prudhoe Bay Unit (North Slope, Alaska), the geochemical model was validated with the laboratory analyses of Zone 4 produced water samples. Then it was used to evaluate the impact of mixing formation brine and seawater on rock-fluid interactions and scale formation. The prediction is consistent with the observation of calcite formation in early production at Prudhoe Bay. The model also predicts the precipitation of iron carbonate and iron sulfide scales as the seawater flood continues.
Turbulent Dispersion in Porous Materials as Modeled by a Mixing Cell with Stagnant Zone
Authors: Kyle C.R. , Perrine R.L. 
Published: December 2007

Abstract
This paper reports on a simple theoretical analysis of dispersion in rapid flow through porous materials, giving a comparison of predicted results with experiments. The analytical model considers a pore structure which acts like a sequence of mixing cells, each coupled with a stagnant zone.
Computed results compare very favorably with experimental observations on flow through a staggered matrix of cylinders. This, in turn, has been shown to behave the packed beds of spheres with corresponding properties. Agreement requires that values for certain theoretical parameters be fitted from the data The values required for these parameters are very reasonable. Development of parameters are very reasonable. Development of this approach could be useful for a number of related problems.

Introduction
The dispersion of two dynamically similar miscible liquids in laminar or turbulent flow through a porous material is a very complex process. However, it can be broken down into four process. However, it can be broken down into four basic mixing mechanisms:
(1) Molecular diffusion. Where the flow velocity is appreciable, or pore size is larger, diffusion is usually negligible. Molecular diffusion will not be discussed in this paper.
(2) Uneven fluid movement due to irregular pore geometry and inhomogeneities in the media. Both of these factors are difficult to treat, and are usually neglected in theoretical analysis.
(3) Uneven fluid movement due to velocity differences within the pores and passages. The zero-velocity boundary condition on each solid surface assures this type of mixing in both laminar and turbulent flow.
(4) Mixing by rotational flow, or by turbulent eddies within the pores or passages.
The last two are both convective mixing processes and depend primarily upon the level of processes and depend primarily upon the level of energy dissipation in the media, as well as on the geometry of the system. In general as the velocity increases and the friction losses rise, so does the efficiency of the mixing process.
Dispersion has been reviewed thoroughly by Perkins and Johnston and has been studied Perkins and Johnston and has been studied extensively by others.