bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Simulation Approach To Validate Petrophysical Data From NMR Imaging
Authors: Zuluaga Elizabeth , Majors Paul D. , Peters Ekwere J. 
Published: December 2007

SummaryNuclear magnetic resonance (NMR) imaging was used to map the 3D porosity and permeability distributions in heterogeneous sandstone cores under controlled laboratory conditions. The porosity and permeability distributions so obtained were used to numerically simulate first-contact miscible displacements in the cores. The spatial and temporal solvent concentrations from the numerical simulations were compared to those from imaging experiments in the cores in an effort to validate the porosity and permeability data. The results show that with calibration, useful 3D porosity and permeability distributions of heterogeneous cores can be derived from NMR imaging (NMRI).
Waterflood Operations in the North Meadow Creek Sussex Sand Unit
Authors: Myers L.B. 
Published: December 2007

Abstract
Basic reservoir data, geological data, and production history are given and a progress report presented on the North Meadow Creek Sussex Sand Unit water flood operation.
Water flood equipment, water supply, water treatment for bacterial control, and operating problems peculiar to Wyoming and the Rocky Mountain area are described. The five operating companies unitized interests for the purpose of water flooding early in the primary life of the reservoir. In Dec., 1953, after four years of primary life, water was initially injected. Four producing wells were converted to input, forming a 40-acre pilot five-spot. Injection well performance in the pilot area has shown the Sussex sand to have adequate receptivity to fresh water at moderate pressure. Injected volumes required for fill-up confirm estimates on water flood efficiency and indicate waterflood recovery will exceed primary.
The pilot was expanded in 1955 to encompass 80 percent of the reservoir productive acreage. Producing wells were converted to input on pattern except where faulting dictated otherwise.

Introduction
This paper is a report on a waterflood operation in the North Meadow Creek field, Johnson County, Wyo. The field, discovered in Dec., 1949, is located in the Powder River Basin near Linch, Wyo., 8 miles northeast of the famous Salt Creek field. Water is being injected into the Sussex sand reservoir at a depth of 4,000 ft. Before commencing the pilot injection test, the five working interest owners in the field unitized the Sussex sand reservoir with unit participation being divided among Delhi-Taylor Oil Corp., Continental Oil Co., American Liberty Oil Co., Mimi Corp., and Murchison Trust.
Although the operation is normal in most respects, it is the only full scale pattern water flood in the Rocky Mountain area. It is also of special interest to note that the operators recognized the adaptability of the Sussex sand to water flooding and unitized for this purpose early in the primary life.
It shall be the purpose of this paper to present basic reservoir and geological characteristics of the Sussex reservoir as well as to discuss operating practices, water supply, flood equipment, and pilot waterflood performance.
Permeability Reduction by Treatment With KUSP1 Biopolymer
Authors: McCool C. S. , Shaw A. K. , Singh Amitabh , Bhattacharya Saibal , Green D. W. , P. Willhite G. 
Published: December 2007

Summary
The application of KUSP1 biopolymer for use in permeability reduction treatments of oil reservoirs was investigated. KUSP1 is a nontoxic polysaccharide that is produced by a bacterium. Alkaline solutions of KUSP1 have low viscosities and can be gelled by different methods. Three methods were examined to gel KUSP1 in porous media. Two of the methods are based on the reduction of pH of alkaline KUSP1 solutions. KUSP1 is soluble in alkali but forms a gel when the pH is lowered to values below 10.8.
The first method employed the hydrolysis of an ester to reduce pH and trigger gelation. Gel times on the order of days were observed for KUSP1 solutions that contained the monoethylphthalate (MEP) ester. The performance of the KUSP1-MEP system in treatments of sandpacks, Berea cores, and carbonate field plugs was studied at 25°C. Brine permeabilities were reduced by factors that ranged from 75 to 4,500. Permeability reduction by treatments with the KUSP1-MEP system was stable to brine flow for periods of up to six months.
The second method to gel alkaline KUSP1 solutions was based on the chemical interactions with rock material. It was found that interactions with Berea sandstone, Baker dolomite, silica sand-packs, and field core plugs were insufficient to reduce the pH of alkaline KUSP1 solutions to values required for gelation.
Alkaline KUSP1 solutions were gelled by the addition of boric acid in the third method. Bulk gelation studies conducted at 25, 45, and 65°C showed that gel times could be regulated up to several days by selection of pH and boric acid concentrations. The gels were more rigid than those produced by pH-reduction methods, indicating a different gelation mechanism. Syneresis was observed and was more pronounced at lower pH values and higher temperatures. The KUSP1-boric acid system reduced brine permeabilities in sandpacks and Berea cores (25, 45°C) by factors that ranged from 50 to 3,300.
Method for Accurately Measuring Produced Oil Volumes During Laboratory Waterflood Tests at Reservoir Conditions
Authors: Hvolboll V.T. 
Published: December 2007

Introduction
Much usable information can be obtained from laboratory waterflood tests conducted at reservoir temperatures and pressures using reservoir fluids. Consequently, reservoir-conditions waterflood tests have been conducted by several laboratories even though such tests are much more difficult and expensive than routine waterflood tests. One of the most difficult problems with these reservoir-conditions tests is measuring incremental and total displaced oil volumes accurately. This study describes a method that produces a continuous record of oil production during a high-pressure, high-temperature waterflood test. With this method, oil is accumulated in a high-pressure separator, where its volume is monitored with a very sensitive differential pressure transducer. If the dimensions of the separator are selected properly, very small volumes (less than 1% of the pore volumes of typical test cores) can be measured reliably using commercially available pressure transducers. The basic method also can be used for tests involving gas displacing oil or water and water displacing gas. With minor modifications of equipment and operating procedures, produced volumes of gas, oil, and water can be measured during three-phase flow tests.
The waterflood technique discussed here now is being used routinely and has proved satisfactory for the past 15 years. Using this method experienced operators easily can record the production history from several core floods running concurrently.

EXPERIMENTAL METHOD
Fig. 1 schematically shows the main items of required equipment. All components are off-the-shelf items except the core holder and high pressure separator, which must be shop built. During a waterflood test, fluid leaving the core enters a high-pressure separator, where produced oil accumulates in a collecting tube. Both the core and separator are in a constant temperature oven. The separator is a blind cell, thus the inconvenience and hazards associated with viewing windows are avoided. The system is designed so only one phase (gas or water is displaced through a backpressure regulator. This design has two advantages over methods that require all production to flow through a regulator:conventional commercial backpressure regulators can be used without modification to reduce holdup volumes andpressure fluctuations at the upstream side of the regulator are reduced significantly so the pressures in the separator and at the outlet end of the core are kept much more uniform.
The difference between pressures at the top of the collecting cube and the top of the annulus is measured with a sensitive differential pressure transducer. The portion of the annulus containing oil and the lines from the separator to the transducer normally are filled with live crude oil. At the start of the test water in the separator should have the same density as the flood water and water initially in the core.
SPEJ
P. 239
Influence of Drillpipe Rotation and Eccentricity on Pressure Drop Over Borehole With Newtonian Liquid During Drilling
Authors: Ooms G. , Kampman-Reinhartz B. E. 
Published: December 2007

SummaryField measurements have revealed that the pressure drop over a borehole during drilling of a slim oil well or a well with a long reach can depend significantly on the rotation speed of the drillpipe. In this paper we discuss analytical, numerical and experimental studies to explain this effect for the case of a Newtonian liquid in the borehole. Special attention is paid to the inertial forces in the liquid (in the annulus), caused by the rotation and eccentricity of the drillpipe. It is concluded that for large values of these inertial forces the axial pressure drop depends significantly on the rotation speed of the drillpipe. A pressure drop simulator (also valid for the case of a non-Newtonian liquid in the borehole) has been developed, that includes this effect and is in good agreement with field test data.
Bacterial Profile Modification With Bulk Dextran Gels Produced by In-Situ Growth and Metabolism ofLeuconostoc Species
Authors: Jenneman G. E. , Lappan R. E. , Webb R. H. 
Published: December 2007

SummaryGrowth of Leuconostoc mesenteroides in a synthetic sucrose-based medium resulted in production of rigid, bulk dextran gels, whereas, growth on a beet-molasses medium produced loose, colloidal gels. Addition of inexpensive protein hydrolysates to the synthetic medium allowed for formation of the best bulk gels. Bulk gel formation was favored by increased bacteria concentrations and harvesting of cells during exponential growth. Bulk dextran gels resulted in greater in-depth permeability reductions (&gt;90%) than those supporting formation of colloidal gels but in-depth gel formation, and plugging in field cores was limited by transport of bacterial cells.
Analysis of a Single-Well Chemical Tracer Test To Measure the Residual Oil Saturation to a Hydrocarbon Miscible Gas Flood at Prudhoe Bay
Authors: Cockin A. P. , Malcolm L. T. , McGuire P. L. , Giordano R. M. , Sitz C. D. 
Published: December 2007

Summary
In 1990, a single-well chemical tracer (SWCT) test was performed in Prudhoe Bay to measure the effective waterflood and miscible gasflood residuals over a 12 ft reservoir interval. This is believed to be the first such use of this technology for a hydrocarbon miscible gas. This paper describes how the usual SWCT design was modified to accommodate the miscible gas, the results of the SWCT, which indicate significantly higher residual oil saturation for miscible gasflood than expected from coreflood experiments, and the subsequent simulation of the test which has provided good agreement with the observed results. The paper shows, with compositional simulation support, that the high apparent residual oil saturation was a consequence of incomplete volumetric sweep by the miscible gas and draws on the experiences of this test to make recommendations for the design of future SWCT tests measuring residuals to gasflooding.
Performance Prediction of Floating Drilling Vessels for Various Operating Areas
Authors: Evans W.M. , Futoma G.A. , Lombana C.A. 
Published: December 2007

This paper describes a computer program, composed of weather and drilling models, that was developed to help select floating drilling vessels for specific operating areas and start-up times. With these models, expected performance of different vessels can be simulated and their costs performance of different vessels can be simulated and their costs compared.

Introduction
Weather conditions vary considerably from area to area and even during the course of a year in a single area. Consequently, drilling vessels that have been used successfully in one region or at one time might not be suitable for different circumstances.
Since the day rate for different vessels also may vary, selection of a proper vessel involves both engineering and economic factors. If expected adverse weather or sea ice place time restraints on operations, reaching a desired place time restraints on operations, reaching a desired well depth by a certain date becomes an important consideration in vessel selection.
Criteria necessary to establish estimated performance of a floating drilling vessel are moron characteristics, operating limits with respect to sea conditions or vessel motion, well design and expected drillability of the formation with no vessel motion, and weather data for the geographical area. This information is incorporated in drilling and weather models that then are combined to calculate predicted performance of the vessel.

Vessel-Motion Characteristics
Heave, roll, and pitch data for a specific vessel are determined from model tests in wave basins or from theoretical calculations. These data usually occur as response-amplitude operators (RAO) for regular waves (Figs. 1 through 3). Since sea conditions are not regular, vessel-motion characteristics in irregular seas must be determined.
As described by Michel and Minkenberg and Gie, vessel motion in irregular seas (heave, pitch, and roll spectra) can be determined by multiplying wave spectral density by the square of the vessel response for a range of frequencies.
The wave spectral density, Sw(w), for a frequency w is given by the Bretschneider spectrum:
4,200 H 2 - 1,050s Ts 4 w 4 Sw(w) = -------------- e, ..............(1)T 4 w5s
where Sw(w) = wave spectral density, sq ft-sec forfrequency wHs = significant wave height, ftTs = significant wave period, secondsw = wave frequency, sec-1.
With this definition, the area under the spectral curve equals the square of the significant wave height. Fig. 4 illustrates this spectrum for a significant wave height of 17 ft and a significant wave period of 10 seconds.
The heave spectrum in Fig. 5 was obtained by multiplying the wave spectral density by the square of the RAO for the corresponding frequency.
Z(w) = Sw(w) . RAO 2 (w),...................(2)
where Z (w)= heave-spectral density, sq ft-sec forfrequency w.
Significant heave, Zs, is obtained by
Zs (Hs, Ts) = Z(w) dw,...................(3)
JPT
P. 1688
Modern Seismic Methods - An Aid for the Petroleum Engineer
Authors: Ausburn B.E. , Nath A.K. , Wittick T.R. 
Published: December 2007

This paper describes the emerging detailed seismic techniques that often can provide considerable help for the petroleum engineer. Five areas of mutual interest for the geophysicist and petroleum engineer are identified. Primary emphasis is on the use of seismic data for reservoir identification.

Introduction
Today, petroleum engineers are faced with unprecedented challenges in every phase of their profession. Increasing costs, more difficult development targets, and exotic recovery techniques make it imperative that the engineer be aware of all available technology for meeting these challenges. Of particular interest are new seismic acquisition, processing, and interpretative techniques that have improved significantly in the last 5 years and now represent an important new exploitation tool. The engineer should be aware of these improved capabilities and should be prepared to use appropriate seismic entry data to help solve his problems.

Summary
Areas of mutual interest for the petroleum engineer and the geophysicist can be summarized as follows.

Exploration/Production Interface
Preparation and Evaluation of Analogs. Petroleum Preparation and Evaluation of Analogs. Petroleum engineers are involved in evaluating existing fields, producing trends, or provinces. The engineer directly producing trends, or provinces. The engineer directly influences exploration efforts by his assessment of the economics of established production, and indirectly influences exploration activities by his evaluation of rock and fluid properties, which are, in turn, used in seismic interpretation.
Development of Velocity and Density Depth Trends From Wellbore Data. Similar to the preparation of analogs, engineers often develop formation parameter trends from which various combinations of earth acoustic properties can be tested. Since the quality of these trends properties can be tested. Since the quality of these trends often depends on the way wells have been drilled, engineers should have some degree of control over data acquisition.
Forecasting. Engineers may influence exploration activities by their forecasts of required drilling/production capital, operating costs, and product prices. However, a forecast of exploration activities influences such engineering predictions as drilling rig and tubular requirements, and production schedules for a trend, province, division, or company.
Bid Preparation and Property Purchases. In most companies, engineers and exploration personnel work together in preparing acreage bids and evaluating property purchases. The engineer must understand the property purchases. The engineer must understand the applications and limitations of seismic data, a principal exploration tool.

Field Development
Extent of Hydrocarbon Accumulation From Lateral and Vertical Limits. Lateral limits include salt face, porosity pinchouts, and faults; vertical limits include porosity pinchouts, and faults; vertical limits include fluid contacts and porosity pinchouts.
JPT
P. 1519
Performance of a Solution Gas Drive Reservoir, Rosenwald Pool, Oklahoma
Authors: Smith M.R. , Henderson J.H. 
Published: December 2007

Abstract
The Rosenwald pool, Okfuskee County, Okla., was discovered in June, 1949. Production is from the Union Valley limestone and Cromwell sand, both of Pennsylvanian age, at an average depth of about 3,450 ft. The Union Valley lies conformably on the Cromwell with the two formations forming a common reservoir. The pool is a stratigraphic trap with the limits defined by a pinchout of the sand and a loss of permeability in the lime. The pool as fully developed consisted of 31 producers drilled on 10-acre spacing.
All wells flowed upon completion, with initial productions ranging from 40 BOPD for edge wells to as much as 1,600 BOPD where good Cromwell sand development was encountered. Initially only a few feet of sand penetration was taken, for fear of encountering bottom water.
Early in the life of the reservoir, performance calculations were made using Muskat's differential form of the material balance equation for dissolved gas drive reservoirs, in an attempt to predict the future production history of the pool. A kg/ko curve for the performance calculations was constructed from data of other pools which have produced from Cromwell or sands similar in texture to the Cromwell. Subsequently the reservoir has been essentially depleted by primary means, enabling a comparison of the actual performance with that predicted. Actual recovery was 20 per cent of the original oil in place as compared to the prediction of 26½ per cent. Laboratory-determined relative permeability ratios and the assumed ratios used in the performance calculations are compared with those calculated from the field performance.
By the end of 1953 most of the wells had become marginal producers and the pool was unitized and is presently being waterflooded.

Introduction
The Rosenwald pool has afforded an excellent opportunity to analyze the performance of a solution gas drive reservoir. This relatively small pool was drilled on 10-acre spacing and had an over-all primary producing life of 41½ years. Care was taken throughout the life of the pool to obtain adequate production and engineering data to enable good comparisons of the actual performance with theoretical concepts.
An Approximate Method for Non -Darcy Radial Gas Flow
Authors: Rowan G. , Clegg M.W. 
Published: December 2007

Abstract
Approximate analytical solutions for non-Darcy radial gas flow are derived for bounded and infinite reservoirs producing at either constant rate or constant pressure. These analytical solutions are compared with published results for non-Darcy flow obtained on digital and analogue computers, and the agreement is shown to be very good. Some observations on the interpretation of gas well tests are made.
Introduction
The flow of gases in porous media is a problem that has been the subject of much study in recent years, and many methods have been proposed for solving the non-linear equations associated with it. The assumption that the flow satisfies Darcy's Law
(1)
leads to a non-linear equation of the form
(2)
in a homogeneous medium, assuming an equation of state(3)
It has been observed, however, that the linear relationship between the flow rate and pressure gradient is only approximately valid even at low flow rates, and that as the flow rate increases the deviations from linearity also increase. It has been suggested by a number of authors that Darcy's Law should be replaced by a quadratic flow law of the form
(4)
This form of equation was first suggested by Forchheimer and, later, Katz and Cornell, and Irmay, developed a similar equation. Houpeurt derived this form of equation using the concept of an idealized pore system in which each channel consists of sequences of truncated cones giving rise to successive restrictive orifices along the channel. This type of representation leads to a quadratic flow law of type, for all fluids, but it is found that the quadratic term is only significant in the case of gas flow. The methods of Houpeurt for solving gas flow problems will be discussed further in another section of this paper.
Solutions of the non-linear equation for Darcy gas flow may be classified as either computer (digital and analogue), or approximate analytical ones. The former include the well-known solutions of Bruce et al., and Aronofsky and Jenkins, but the latter solutions, apart from the simple linearization of equation [2] to yield a diffusion equation in p2, are not so well-known.
SPEJ
P. 96ˆ
Roughness of Hydraulic Fractures: Importance of In-Situ Stress and Tip Processes
Authors: van Dam D. B. , de Pater C. J. 
Published: December 2007

SummaryThe surface roughness of hydraulic fractures reflects the fracturing process at the tip. We conducted an experimental study of hydraulic fracture propagation and observed a characteristic roughness pattern. The roughness developed without shear or torsional loading in the plane of the penny-shaped fracture and is determined by material properties and the externally applied stresses on the sample, which represent the effective in-situ stresses. We quantified the roughness and showed that it correlated well with a measure of the plastic zone size around the fracture tip. New explanations for fracture surface roughness that develops under Mode I loading conditions are presented.