bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of Geothermal Wells in Naturally Fractured Formations With Rate-Sensitive Flow
Authors: Morris C. W. , Campbell D. A. , Petty S. 
Published: December 2007

Summary
Production data are presented that show the nonlinear flow behavior for high-rate geothermal wells in liquid-dominated, naturally fractured formations, and comparisons are made between various theories for describing this rate-sensitive phenomenon. The test data indicate that the pressure drawdown relationship with flow rate has a component proportional to flow rate, squared. Two fracture-closure theories gave inadequate results for predicting well performance.
A New High-Speed Hybrid Technique for Simulation and Inversion of Resistivity Logs
Authors: Glanzero Stan , Lin Ylh-ylh , Su Shey-Min 
Published: December 2007

Summary
The inversion of resistivity logs with multiple bed boundaries is of vital interest to log analysts, but previously published methods have been optimized for cases of many radial boundaries with a serious loss of speed when many bed boundaries are considered. This paper describes a hybrid solution (analytic radially and numeric vertically) that can simulate a 100-ft [30.4-m] log with 25 beds in less than 12 minutes on an IBM 3081.
The model assumes axial symmetry with no dip and with the tool centered in the borehole. Decomposition of the measured potential into the product of two independent functions describing its radial and axial dependence allows us to choose the best method for evaluating each function. For the case dominated by bed boundaries, the most efficient choice is to obtain the radial solution analytically by means of a finite number of modes and to obtain the axial solution using piecewise continuous functions.
Several simulations are presented of the dual laterolog (DLL) in multibed cases with invasion, and the results are combined in a least-squares inversion technique to demonstrate the derivation of true resistivity profiles from real logs.
Pressure Analysis for Horizontal Wells
Authors: Daviau F. , Mouronval G. , Bourdarot G. , Curutchet P. 
Published: December 2007

Summary
This paper presents horizontal-well test design and interpretation methods. Analytical solutions are developed that can be handled easily by a desktop computer to carry out design as well as interpretation with semilog and log-log analysis. These analytical solutions point out the distinctive behavior of horizontal wells: (1) at early time, there is a circular radial flow in a vertical plane perpendicular to the Well, and (2) at late time, there is a horizontal pseudoradial flow. Each type of flow is associated with a semilog straight line to which semilog analysis has to be adapted. The horizontal pseudoradial flow takes into account a pseudoskin depending on system geometry, which is a priori defined and estimated. Practical time criteria are proposed to determine the beginning and the end of each type of flow and to provide a guide to semilog analysis and well test design.
We study the behavior of uniform-flux or infinite-conductivity horizontal wells, with wellbore storage and skin. The homogeneous reservoir is infinite or limited by impermeable or constant-pressure boundaries. A method is also outlined to transform all our solutions for homogeneous reservoirs into corresponding solutions for double-porosity reservoirs.
Application of Closed-Chamber Theory to Backsurge Completion Testing
Authors: Simmons J. F. , Grader A. S. 
Published: December 2007

Summary
This paper presents a transient-pressure analysis method for the closed-chamber oilwell test. This method allows determination of reservoir transmissivity and wellbore skin with log-log type-curve matching. The method is believed to be applicable to analysis of perforation-cleaning backsurge data. A solution is obtained by superposition of the cumulative-influx, constant-pressure solution of the radial diffusivity equation. Superposition avoids many of the limitations of direct solution and facilitates consideration of nonideal chamber gas behavior and complex wellbore geometry.
A sensitivity study of tool and reservoir parameters is presented. The results indicate that unlike the slug test, tool geometry greatly influences the dimensionless-pressure response of the closed-chamber test. Tool design guidelines are presented for extending the period during which the closed-chamber test behaves as a slug test and is suitable for analysis by type-curve matching with published slug-test results. The superposition results also indicate that assuming ideal chamber gas behavior does not significantly alter the bottoihhole-pressure (BHP) response.
A Comparison of Shaly-Sand Interpretation Techniques in the Mesaverde Group of the Uinta Basin, Utah
Authors: Chisholm J. L. , Schenewerk P. A. , Donaldson E. C. 
Published: December 2007

Summary
The methods available for the interpretation of well logs in shaly sandstones are numerous. Deciding which methods to apply in a given area or formation is often difficult. A cation-exchange-capacity (CEC) correlation is presented for the Mesaverde group of the Uinta basin, Utah. Three porosity estimators are compared with core porosities. Nine water-saturation estimators are compared with Waxman-Smits water saturations.
Surfactant Flooding With Hard Water: A Case Study Solved by HLB Gradient
Authors: Minssieux Louis 
Published: December 2007

Summary
Surfactant formulations were designed for field application of micellar processes in a salty environment on the basis of a mixture of one synthetic sulfonate with two types of nonionic agents. This formulation led to the required Winsor-III-type phase diagram in the presence of reservoir fluids at reservoir temperature. The main difficulty in this study was the high level of surfactant retention in the reservoir rock. The sacrificial agents tested did not reduce these surfactant losses significantly. The solution found to be efficient consisted of creating a hydrophile-lipophile balance (HLB) gradient of the additives used in situ by injecting a desorbing agent with high HLB behind the micellar slug containing the nonionic cosurfactants with lower HLB. The interpretation proposed for such a procedure shows that the mechanisms involved produce the same beneficial effects as the salinity gradient technique. The good results obtained indicate the potential importance of the HLB gradient when the salinity gradient cannot be used in the micellar processes under consideration.
Practical Considerations When Reservoir Boundaries Are Encountered During Well Testing
Authors: Moser H. 
Published: December 2007

SummarySemilog type-curve matching applied to drawdown, desuperposed drawdown, Miller-Dyes-Hutchinson (MDH), and Matthews-Brons-Hazebroek (MBH) plots can determine drainage shape and the outer boundary conditions of a well. Because only a single set of type curves for a particular drainage-shape/outer-boundary condition is necessary, the selection of a proper well-test model is straightforward.Additionally, the porosity/compressibility/area product and the skin effect can be estimated with a semilog type-curve match. Furthermore, a generalized form of desuperposition has been applied when the duration of the buildup is a multiple of the drawdown period. This method eliminates the use of all drawdown pressures except at the moment of shut-in. Therefore, variable skin effect during drawdown (e.g., cleanup) can be analyzed.
Correlation of Oil Formation Volume Factor and Solution Gas-Oil Ratio
Authors: Knopp C.R. , Ramsey L.A. 
Published: December 2007

Abstract
Thermally-reduced oil formation volume factor is correlated with solution gas-oil ratio from 0 to 3,500 cu ft/bbl. This correlation was made from the differential liberation curves of 159 analyses of saturated Eastern Venezuelan crudes. Average error, determined by comparing correlation and calculated with the laboratory-determined oil formation volume factor, was found to be 2.00 per cent. Average error of 104 separator flash tests was 1.97 per cent.

Introduction
Based on the original method of Katz, a correlation of thermally-reduced oil formation volume factor and solution gas-oil ratio has been made from saturated Eastern Venezuelan crudes. The accuracy of this correlation, which requires a minimum amount of data and is easy to use, is sufficient for most reserves estimates. The average correlation error of 2.00 per cent for reservoir differential data compares closely with the 1.97 per cent error for separator flash data.
While the accuracy of this correlation for other oil-producing areas is not known, there is close agreement with the general correlation of Katz. Also, there is a wide crude-oil gravity range represented, 15 degrees to 47.5 degrees API, with reservoir temperatures that range from 142 degrees to 307 degrees F. It is thought, therefore, that this correlation can be universally applied with reasonable accuracy. Wherever sufficient data exist, a cross plot can quite easily be made so that an area-oriented correlation is obtained.

Construction and Error
Fig. 1 is a correlation obtained from 159 differential liberation curves of saturated Eastern Venezuelan crudes. This correlation closely parallels the Katz general correlation previously made to a maximum solution ratio of 1,300 cu ft/bbl. Data obtained from volatile Venezuelan crudes shows that this correlation can be extended to 3,500 cu ft/bbl with good data conformance. The extension of the correlation is almost linear. Data used in Fig. 1 represent crude oils which range from 15 degrees to 47.5 degrees API. Reservoir temperatures of these crudes range from 142 degrees to 307 degrees F.
Natural Convection in Porous Media and Its Effect On Segregated Forward Combustion
Authors: Dirksen C. 
Published: December 2007

Abstract
This study investigates whether oxygen consumption during segregated forward combustion may be affected by natural convection. Linear theory indicates that thermal instability occurs in a horizontal porous medium when the modified Rayleigh number N'Ra exceeds a critical value of about 40. Most experimental results, including those described here. indicate this value to be about an order of magnitude smaller. N'Ra is derived from "differential similarity" and the proper time scale factor is also obtained.
The critical value of N'Ra for a horizontal, water-saturated porous medium at atmospheric pressure subjected to a vertical temperature gradient was found to be about 3.0. The ambiguity in the value of N'Ra arising when fluid properties cannot be assumed constant is indicated. Natural convection was observed for oblique systems below N'Ra while simultaneous horizontal flow did not affect N'Racrit.
The expected range of values for the various parameters pertaining to segregated forward combustion is indicated and the corresponding values of N'Ra calculated. Only under very favorable conditions, such as high permeability, high pressure and low top temperature, can the critical value of N'Ra be exceeded. Thickness of the convection layer should not become too large. since the time required to obtain significant mixing is proportional to the square of the thickness. For an oblique combustion front the conditions for significant mixing may be less strenuous.

INTRODUCTION
Laboratory1,2 and field3,4 experiments have shown that a markedly upgraded oil can be produced by in situ forward combustion. Under certain conditions injected air may move through a high permeability, gas-saturated channel over the oil-saturated layer, while combustion takes place, exclusively, at the horizontal interface (Fig. 1). Such a channel may be a natural gas cap, or, it may result from a forward combustion process in which injected air and combustion gases fingered through the top of the formation, causing a premature breakthrough at the production well.
In this particular case of segregated forward combustion, the air stream moves parallel to the combustion front. Molecular diffusion and transverse mechanical dispersion will be insufficient to cause all the oxygen in the air stream to reach the combustion front. When the oxygen in the air stream is not completely consumed in the combustion process, it will reach the production well and create a serious fire hazard. In addition, the reduced efficiency may make the process economically unprofitable while also serious corrosion problems may be experienced in the production well.3 This undesirable situation should, therefore, be prevented.
Drilling the Cold Lake Horizontal Well Pilot No. 2
Authors: MacDonald Ron R. 
Published: December 2007

Summary
Esso Resources Canada Ltd. drilled its second horizontal well at Cold Lake, this time achieving a 1016-m [3,333-ft] horizontal interval. Two key limitations—hole drag and wellbore position accuracy—required special attention. The well design and the methods planned to accommodate these limitations are compared with the actual well data.
Multiple-Contact Phase Behavior Measurement and Application With Mixtures of CO2 and Highly Asphaltic Crude
Authors: Bryant D. W. , Monger T. G. 
Published: December 2007

Summary
This paper is an experimental study of the phase behavior relevant to CO2 flooding for multiple-contact miscible, immiscible, or huff 'n' puff applications. Unique features of this investigation are that the live reservoir oil was highly asphaltic and was modified to resemble the composition likely contacted by injected CO2. Single-contact and two types of multiple-contact PVT data are presented, and the usefulness of such data in predicting CO2 flood performance is discussed.
The results show no liquid/liquid/vapor (L/L/V) three-phase region at higher temperatures and no liquid/liquid (L/L) critical point. Large CO2 concentrations were required before substantial hydrocarbon extraction occurred. A ternary diagram representation of forward multiple-contact compositional results indicates that CO2 generated miscibility with the oil by the vaporization mechanism. Precipitation of a tar-like, highly aromatic solid was associated with the development of miscibility. This solid phase represented approximately 20 wt% of the stock-tank-oil hydrocarbon. The swept-zone multiple-contact results show a cumulative liquid volume production of about 35% of the original oil in place (OOIP) after the second CO2 contact, with further contacts recovering essentially no additional oil. The residual oil was composed of heavy, aromatic hydrocarbon.
Flow-Testing Coalbed Methane Production Wells in the Presence of Water and Gas
Authors: McKee C. R. , Bumb A. C. 
Published: December 2007

Summary
When water pressure is lowered to allow coalbed methane to desorb and flow to the well, three distinct flow regimes can be identified: (1) saturated water flow with no gas phase; (2) unsaturated water flow with an immobile gas phase; and (3) two-phase flow of gas and water. This paper derives a solution that includes the first two regimes in a single formula. The concept of parameter measurement windows is introduced and applied to analyze data from Glover Well 1 Drawdown Test 2 to obtain additional information on relative permeability and saturation curves. An increase in slope, which was initially attributed to other causes, is explained as a relative permeability effect.
A New Digital Multiscale Pulsed Neutron Logging System
Authors: Randall R. R. , Gray T. P. , Craik G. C. , Hopkinson E. C. 
Published: December 2007

Summary
A new multiscale pulsed neutron capture logging system (PDKSM-100) is discussed. The instrument is a 11116-in. [1.7-cm] -diameter, microprocessor-controlled logging sonde that processes raw data occurring in the short-and long-spaced detectors. The timing spectrum (10 μsec per channel and 100 channels for the decay component) of the detector events is accumulated downhole and transmitted to the surface computer logging system upon command by a pulse code modulation data transmission system. This configuration makes use of significantly increased count rates to improve log repeatability greatly. Unique data reduction techniques are also possible with the high-resolution data.
The gamma rays during the burst of 14-MeV neutrons are also processed. This unique feature allows derivation of the ratio of inelastic to capture count rates, which is a function of porosity.
All conventional pulsed neutron capture (PNC) responses can be observed with the new pulsed neutron logging (PNL) system. However, many additional aspects of formation evaluation are possible as well. Several of the more unique features of the system are demonstrated in specific log examples.
A Key to the Future - A Review of the Economics of the U.S. Oil Producing Industry
Authors: Priestman G. Dawson 
Published: December 2007

Introduction
Most oil men are keenly concerned with the outlook for the domestic producer. Will production increase? Will profits improve? How long will spare capacity be a problem?
In seeking answers to these and similar related questions, the oil-producing industry needs a much clearer picture of long-term trends. Unfortunately, such a picture has not been readily available due largely to a lack of reliable industry data. But some things are obvious-over the last 10 years, expenditures have increased considerably and over-all profits on new investments have declined. This trend has raised many questions regarding the economics of the industry, and in recent years a new profession has appeared-exploration and producing economics. Basically, the function of the producing economist is to analyze the trends of the past to find "a key to the future".
This paper offers an analytical approach to the economics of the United States oil-producing industry over the past 20 years. While the methods used may not be fool-proof, they are believed to give a reasonable appraisal of the situation as it has existed.
Two basic factors, "income" and "expenditures", must be understood when analyzing an industry or a company. The relationship between income and expenditures gives "profit", the motivating force behind the free-enterprise system. These factors, although they sound simple, are often difficult to interrelate, especially in the petroleum industry. It is important that they be known and recognized, not only for individual or company use, but also in efforts to explain their significance to the public and to Congress.
Microcomputer Applications in the Drilling Industry
Authors: Berkson Brad , Shoham Ovadia 
Published: December 2007

Summary
The popularity and usefulness of the microcomputers are rapidly increasing. This tool has many applications which are pertinent to the drilling industry. Software and hardware for drilling uses are finding their way into the field. Lotus 1-2-3 is one of the many microcomputer software packages that has uses in the drilling business. Two programs using Lotus 1-2-3 were developed in this study for application in drilling. The first is a drill bit hydraulics optimization spreadsheet, and the second is a graphics macro for generating curves of well depth vs. number of drilling days. Both programs demonstrate the distinct advantages of applying microcomputers in the oil industry.

Introduction
The recent boom in microcomputers has opened the avenue to many uses of microcomputers in the oil industry. Their applications in the drilling industry in particular are just now being realized. Micros can be used in all facets of the drilling business to do anything from economic planning and analysis to bit efficiency and Measurement While Drilling (MWD) monitoring. These computers can manipulate technical and economic data so quickly and cheaply that they are fast becoming invaluable in today's highly competitive economy.
Some of the advances applicable in the drilling field include: 1. Economic and Financial Applications. These applications are key to the main purpose of drilling-profitability. Current spreadsheet software can enable a drilling contractor to speed cash flow analysis, inventory control, and track revenue and expenses. Also, accurate records of equipment can be kept for both depreciation and maintenance purposes.
Operation of a Dry-Desiccant Type Hydrocarbon Recovery Unit
Authors: Drake Q.S. , Dawson E.R. 
Published: December 2007

Introduction
The dry-desiccant type of hydrocarbon recovery and dehydration unit has been on the market in the oil and gas industry for several years, but not until the last few years have developments on the unit been such as to justify more than a passing glance. Prior to this, the operator's main concern was to dehydrate gas to meet the pipeline specification for water-vapor content; any distillate recovered was considered a bonus. That is not the case today.
Companies have come to expect this unit to "pay its way" and to show a profit beyond the initial cost of the unit, as well as to dehydrate the gas. There now is no reason for allowing heavy hydrocarbons to be delivered to a natural gas pipeline for a price which is about 1/20th of its value if recovered as a stock-tank product.

Structural Characteristics of the Unit
Though the main concern here is with the operational characteristics, it will be helpful to give a brief description of the unit. The unit is fully automatic, skid-mounted and (with the exception of the regeneration gas heater) is self-contained. (See Fig. 1.) In this operation, the gas flows from the wellheads to conventional high-pressure separators and into the unit. Here the gas alternately passes through two vertical adsorption towers, which are packed with silica gel, and goes from there to the gas sales line. While one tower is adsorbing the distillate and water, the other is being regenerated in preparation for adsorption. In the regenerating tower, the liquids are being removed from the desiccant by circulating heated regeneration gas. This heated regeneration gas causes the adsorbed liquids to vaporize and be carried out with the regeneration gas. These vapors are cooled through heat exchangers to a liquid state and separated in the regeneration gas scrubber. The separated liquids are then staged to a stabilizer tower (or to a low-pressure separator) and then on to the stock tank. The gas from the regeneration gas scrubber returns to the gas pump suction. Thus, this unit is operating by what is termed a closed regeneration system; i.e., the regeneration gas is in a separate closed system from the main gas stream and is used over and over for regeneration.
Liquid Propellant Stimulation: Case Studies in Shallow Appalachian Basin Wells
Authors: Watson S. C. , Benson G. R. , Fillo G. J. 
Published: December 2007

Summary
Stimulation trials have been conducted on more than 87 oil and/or gas wells in the Appalachian basin with a new liquid propellant. The liquid propellant differs from high explosives in that it is not cap-sensitive and it exhibits a detonation velocity and shock-wave energy like a solid propellant. However, it differs from solid propellants in that it does not require center priming or water-tight containers and generates a high gaseous expansion energy per unit volume like an explosive.