bluuebunny/crossref_metadata_2025_split huggingface dataset:
Varied Applications of Invert Emulsion Muds
Authors: Gray George R. , Grioni Sergio 
Published: December 2007

Invert emulsion muds, compounded so as to have specific properties, can solve such divergent problems as are encountered in producing from water-sensitive pay zones; in drilling formations that dissolve, disperse and disintegrate in water; and in alleviating pipe corrosion.

Introduction
Within the last 7 years there has been a significant increase in the use of drilling and completion fluids having oil as the continuous phase. This extension in applications for oil-base muds has been due in large measure to the development of products designed to provide specific properties. Users are no longer provide specific properties. Users are no longer restricted to certain proprietary mixtures but can devise a suitable composition to satisfy the immediate requirements in much the same way as is done with water muds.
"Oil mud" has oil as the continuous phase. AH oil muds after use contain some water. The term "invert emulsion" often is applied to oil muds having water as a component that has been added to produce a desired property. In this discussion, the term "oil mud" is applied without regard to specific water content, with the limitation that the filtrate is all oil under the conditions of use.
Our purpose is to review briefly some of the varied applications for oil muds and thereby to demonstrate the wide adaptability of these compositions.
Oil muds are not to be regarded as cure-alls for every type of drilling and completion problem. On the contrary, before the decision is made to use an oil mud, attention should be given to specific local conditions. Factors such as potential loss of circulation and rapid accumulation of drilled solids or inclusion of excessive amounts of water in the oil mud affect the economic practicability. Nor should oil muds be used without due regard to the importance of the rig equipment - specifically, facilities for mud mixing, removal of drill cuttings, storage, and the like. Qualified supervision is a necessity, of course.

Oil Mud Additives for Specific Functions
With the objective of affording oil mud compositions as versatile as water muds, products have been developed to control various properties. These products are:Gelling and suspending agents organophilic clays.Emulsifiers: anionic mixed calcium and sodium soaps of fatty acids; cationic amine derivative stable to salts and high temperature.Oil-wetting agent: organic phosphate.Filtration control agent: nonasphaltic oil- dispersible organic colloid.
The development and characteristic properties of these materials have been dealt with in detail in several publications and will not be reviewed here.
The selection of an oil mud for drilling or completion usually involves the recognition of a problem with water muds and the conclusion that savings will result from using the product of higher unit cost. Frequently, the use of oil mud to solve the basic problem brings equal or greater associated benefits.
JPT
P. 261
Correlation of PVT Properties for UAE Crudes
Authors: Dokla Mahmoud E. , Osman Mohammad E. 
Published: December 2007

Summary
Available PVT data from UAE reservoirs was used to obtain correlation equations for bubblepoint pressure and oil FVF as functions of oil specific gravity, gas gravity, solution GOR, and reservoir temperature. Error bounds of the obtained correlations are calculated and compared with other available correlations. The correlations of this study result in lower errors and should work better for UAE crudes.
Impact of Gelation pH, Rock Permeability, and Lithology on the Performance of a Monomer-Based Gel
Authors: Seright R. S. , Martin F. D. 
Published: December 2007

Summary
Resorcinol/formaldehyde gels are used to show that gel performance in porous rocks depends critically on the pH at which gelation occurs. The gels generally reduced the permeability of low-permeability sandstone more than in high-permeability sandstone. However, residual resistance factors can be greater in sandstones than in less permeable carbonate cores. A simple mathematical model is used to assess whether pH effects can be exploited to optimize gel placement in injection wells.
Surfactant-Enhanced Alkaline Flooding: Buffering at Intermediate Alkaline pH
Authors: Rudin Jeff , Wasan Darsh T. 
Published: December 2007

Summary
An experimental investigation of buffered alkaline flooding system chemistry was undertaken to determine the influence of various species present on interfacial tension (IFT) as a function of pH and ionic strength. IFT was found to go through an ultralow minimum in certain pH ranges. This synergism results from simultaneous adsorption of un-ionized and ionized acid species on the interface.
Adsorption of Asphaltenes and Its Effect on Oil Production
Authors: González Gaspar , Travalloni-Louvisse Ana Maria 
Published: December 2007

Summary
Asphaltenes show moderate capacity to reduce oil/water interfacial tension (IFT) and/or to stabilize emulsions. However, in the presence of other surfactants and fine particles presenting intermediate wettability, these compounds enhance emulsion formation and stability. At the solid/solution interface, asphaltenes adsorb up to a saturation value of 2 to 3 mg/g and modify the mineral wettability. At the oil/gas interface, the asphaltic fractions adsorb as single molecules or as liquid crystalline phases, causing foaming problems.
CT-Scan-Monitored Electrical-Resistivity Measurements Show Problems Achieving Homogeneous Saturation
Authors: Sprunt E. S. , Desai K. P. , Coles M. E. , Davis R. M. , Muegge E. L. 
Published: December 2007

Summary
X-ray computerized tomography (CT) scans obtained during measurement of the electrical resistivity of core samples revealed some problems in obtaining uniform saturation along the lengths of the samples. The electrical resistivity of core samples is measured as a function of water saturation to determine the saturation exponent used in electric-log interpretation. An assumption in such tests is that the water saturation is uniformly distributed. Failure of this assumption can result in errors in the determination of the saturation exponent. Three problems were identified in obtaining homogeneous water saturation in two samples of a Middle Eastern carbonate grainstone: a stationary front formed in one sample at 1-psi oil/brine capillary pressure, a moving front formed at oil/brine capillary pressure ≤4 psi in samples tested in fresh mixed-wettability and cleaned water-wet states, and the heterogeneous fluid distribution caused by a rapidly moving front did not dissipate when the capillary pressure was eliminated in the samples.
Optimization of Fracture Length and Well Spacing in Heterogeneous Reservoirs
Authors: Meehan D. N. 
Published: December 2007

AbstractWell spacing and hydraulic fracture treatment designs are the two most important operator-controlled factors in the development of low permeability gas reservoirs. Prior studies of optimization of fracture length and well spacing assumed homogeneous permeability, porosity, thickness, etc. This analysis illustrates the importance of understanding spatial variability of permeability and permeability anisotropy. Geostatistical techniques are incorporated with economic and reservoir modelling to show the quantitative value of reservoir description in tight gas reservoirs.
Design of the HCl Preflush in Sandstone Acidizing
Authors: Hill A. D. , Sepehrnoori Kamy , Wu P. Y. 
Published: December 2007

Summary
HCl usually precedes an HF/HCl mixture in the sandstone acidizing process to reduce HF consumption by carbonates and to avoid the precipitation of HF reaction products. Assuming equilibrium reactions between injected HCl and calcium carbonate in a sandstone formation, we developed a numerical model of HCl frontal movement in the radial direction from the wellbore and added it to an existing sandstone acidizing simulator. In general, only small preflush volumes (as little as 25 gal/ft can be adequate) are needed to prevent live HF from coming in contact with high-pH regions. In almost all treatments, however, spent HF will penetrate beyond the live HCl front; larger HCl preflushes displace the region where spent HF comes in contact with undissolved carbonates in the formation farther from the wellbore. The new simulator predicts the distribution of HCl and HF in a multilayered formation with damage around the wellbore. Using this model, we investigated the required size of the HCl preflush for a range of initial concentrations of HCl and carbonate. We also studied the influence of fluid diversion on the HCl frontal locations in multilayered reservoirs for multiple sequence treatments. In particular, we simulated treatments where HCl was injected without diversion, followed by an HF/HCl sequence including diverting agent to determine whether the HF would be diverted to regions that had not been reached by HCl.
Leak Before Break of CRA Tubing in Sour Environments
Authors: Chen W-C. , Sisak W. J. , Petersen C. W. 
Published: December 2007

Summary
This paper demonstrates that net-section yielding controls the fracture of corrosion-resistant-alloy (CRA) tubulars. Fracture modes observed in actual tests of CRA tubes in sour environments agree with net-section yielding predictions. The paper also shows that leak before break of production tubing in certain sour environments can be achieved with commercially available CRA tubulars.
Esperson Dome Oxygen Combustion Pilot Test: Postburn Coring Results
Authors: Choquette S. P. , Krishnaswamy Sampath , Northrop P. S. , Edwards J. T. , Hooman Laall , Bret Rowland , Morrow D. 
Published: December 2007

Summary
Postburn corehole data from an O2 combustion pilot test in Esperson Dome field, Liberty County, TX, show that the combustion temperature was 930 to 1, 020°F. Final oil saturation was 0% in the burned zone and 11% to 34% in the sand adjacent to the burned zone. Roughly 49, 000 bbl of incremental oil was produced at an injected O2/produced-oil ratio of 4.1 Mscf/bbl.
3D PDC Bit Model Predicts Higher Cutter Loads
Authors: Behr S. M. , Warren T. M. , Sinor L. A. , Brett J. F. 
Published: December 2007

Summary
Historically, PDC bit modeling has incorporated the assumption that cutter forces are constant for a full revolution of the bit. This assumption places considerable limits on the model's ability to simulate drilling in nonhomogeneous rock and in cases where the bit whirls. Recent studies have shown that cutter damage caused by impact loading is a primary cause of PDC bit failure. These impacts may be caused by both bit whirl and drilling through nonhomogeneous rock. The 3D model presented provides the capability to evaluate cutter loading for both conditions. It shows that the cutter loads for common drilling situations may be as much as 10 times greater than those calculated with previously available 2D models.
Field Studies of Circulating Temperatures Under Cementing Conditions
Authors: Davies S. N. , Gunningham M. M. , Bittleston S. H. , Guillot Frederic , Swanson B. W. 
Published: December 2007

Summary
One of the most important but least well-known parameters in cementing operations is the circulating temperature. Many authors have presented theoretical analyses of the wellbore conditions, formulated mathematical models, and presented actual field measurements. However, very little temperature data have been reported for conditions of greatest concern (i.e., with casing in hole). To gather such data in detail, circulating temperature and pressure measurements were made with downhole tools lowered on wireline. In one case, temperature measurements were made during circulation immediately before cementing to record the circulating temperature in the well. In another case, measurements were made after the slurry was been placed to record the thermal recovery of the well. Data collected during these field trials (with casing in hole) are presented and demonstrate the different thermal response of a well with casing instead of drillpipe in the hole. Measured circulating temperatures are lower than those derived from the API schedules and highlight the necessity to account for well geometry properly when determining downhole temperatures.
Troll Horizontal Well Tests Demoristrate Large Production Potential From Thin Oil Zones
Authors: Seines Knut , Lien S. C. , Haug B. T. 
Published: December 2007

Summary
This paper presents the results of two long-term horizontal well tests in the Troll field. Planning and evaluation of the tests and simulation of and consequences on field development are summarized. The two tests demonstrated significant production potential from 12- to 22-m oil columns and verified the pretest assumption that one horizontal well could replace four vertical wells.
Extended Production Tests in the Liuhua 11-1 Reservoir
Authors: Peng C. P. , Bateman C. F. , Kaffenes J. M. , Yanosik J. L. , Huan-Min Liu 
Published: December 2007

Summary
Amoco Production Co. and Chinese Offshore Nanhai East Corp. have conducted three extended production tests (EPT's) on the Liuhua 11-1 reservoir offshore China in the South China Sea. The wells selected for these EPT's included a vertical well, a high-angle deviated well, and a long horizontal well. This paper presents results and analyses of these EPT's.
What Price Quality—The Implementation of the API Quality Program for Drilling-Fluid Materials
Authors: Davis Neal , Perricone A. C. , Warnack M. F. , Grantham C. K. , Hale A. H. 
Published: December 2007

SummaryIn 1985, the American Petroleum Inst. (API) issued the first edition of API Spec. Q1, which dealt with new certification procedures for equipment and materials. This paper discusses API's Spec. Q1 program as it relates to drilling-fluid products and reveals the problems encountered when API Spec. 13A was modified.
Performance of Electric Submersible Pumps in Gassy Wells
Authors: Sachdeva Rajesh , Doty D. R. , Schmidt Zellmir 
Published: December 2007

Summary
A comprehensive investigation was undertaken to study two-phase flow in a radial electric submersible pump (ESP) using diesel/CO2 mixture data from an earlier study. Currently, no dynamic model is available for multistage pumps. A dynamic five-equation model was developed and verified. The model incorporates pump geometry, stage inlet pressure, inlet void fraction, fluid properties, and number of stages. The two-phase flow physics for the pump is found to be vastly different from that in pipe flow. Insights into a pump's surging tendency were obtained.
Rheological Characterization of Hydraulic Fracturing Slurries
Authors: Shah S. N. 
Published: December 2007

Summary
Few studies have dealt with the flow behavior of concentrated suspensions or slurries prepared with non-Newtonian carrier fluids. Therefore, the purpose of this investigation is to present experimental results obtained by pumping various hydraulic fracturing slurries into a fracture model and gathering data on differential pressure vs. flow rate. Several concentrations of hydroxypropyl guar (HPG), a wide range of proppant concentrations, and three test temperatures were studied. The effects of such variables as polymer gelling-agent concentration, proppant concentration, test temperature, and fracture-flow shear rate on the rheological properties of slurries were investigated. The correlations for predicting the relative slurry viscosity for these HPG fluids are presented. Substantial increases in viscosity of fracturing gels were observed, and results are discussed in light of several affecting variables. Results also are compared with those available for Newtonian and non-Newtonian concentrated suspensions. Application of these correlations to estimate the hindered particle-settling velocity in the fracture caused by the presence of surrounding particles also is discussed. The correlations presented can easily be included in any currently available 2D or 3D fracture-design simulators; thus, the information can be applied directly to predict fracture geometry and extension.
Effects of Nonstandard Operating Conditions on the Accuracy of Orifice Meters
Authors: Ting V. C. 
Published: December 2007

Summary
This paper presents the effects of four nonstandard operating conditions on orifice-meter gas-flow measurement accuracy: reversed orifice plates, bent orifice plates, surface roughness on the orifice-meter tubes, and liquid entrainment in the orifice-meter tubes. These are common problems in fields not operating in accordance with the ANSI/API 2530 [American Gas Assn. (AGA) Report 3] orifice-metering standard. This paper provides information to stress prudent operating practices that will reduce measurement errors.
Offshore Oilfield Development Planning
Authors: Behrenbruch Peter 
Published: December 2007

Summary
This paper presents general guidelines to determine the feasibility of offshore petroleum projects in terms of field appraisal, subsurface development planning, and facilities options. It also illustrates the multidisciplinary nature of various tasks and includes examples for illustration. The emphasis is on oil fields, particularly marginal fields.

Introduction
The life of every oil and gas field begins with its discovery. Almost immediately, we want to know what its potential is (in terms of reserves and monetary value) and what the development options are in terms of subsurface plan and facilities.
To answer these questions, a systematic approach is required to evaluate the discovery, to forecast the reservoir behavior under expected producing conditions, and to design the optimum facilities to meet forecasted production. This paper outlines the required process for studying the feasibility of developing offshore petroleum fields.
A petroleum development project typically is divided into a number of major phases: exploration (including permit acquisition), field appraisal (primary and possibly secondary), feasibility study, project implementation (construction), and field production (operation and maintenance, management, and facilities upgrades, including secondary development phases). Different technical departments, each with specific aims, usually manage these phases (Fig. 1).
While the development sequence is similar for all fields, there are notable differences between onshore and offshore projects. Most significantly, the engineering requirements and capital expenditure tend to be one or two orders of magnitude greater for offshore projects than onshore developments. Furthermore, offshore developments tend to have a much longer development schedule before they come on stream. Reserves and well productivity need to be substantially greater for offshore projects to cover the greater capital expenditure and operating cost, respectively.
Development of Hydrodynamic-Model-Based Air-Drilling Design Procedures
Authors: Shifeng Tian , Adewumi M. A. 
Published: December 2007

SummaryThe lack of systematic analysis of the hydraulics involved in air drilling has inihibited the development and utilization of air-drilling technology because the optimal design of any drilling program requires thorough knowledge of the wellbore hydraulics. A comprehensive study of air-drilling hydraulics yielded the system model used as the basis for a viable systematic set of design procedures. The system model was developed by coupling the models for air flow in the drillstring, air flow through the bit nozzles, and pneumatic transport of cuttings in the annulus. The resulting system model was used to design an air-drilling program. A set of design procedures is outlined to predict the standpipe pressure, to estimate maximum well depth, and to determine the optimal air flow rate required in air drilling. Practical examples are presented to test these design procedures.
Static Reservoir Temperature Determination From Transient Data After Mud Circulation
Authors: Hasan A. R. , Kabir C. S. 
Published: December 2007

Summary
The current method for estimating the static reservoir temperature from transient data gathered downhole after the cessation of mud circulation is a Horner-type approach. The reservoir temperature estimate so established generally turns out to be lower than the true temperature. This work shows that the temperature analog of the Horner method is limited to large circulation-time situations and is not applicable to cases where the mud circulation time is generally short (less than 30 hours). This study provides a general solution of the thermal diffusivity equation obtained with an appropriate inner-boundary condition to solve the early-time, transient heat-transfer problem. An analytical solution was developed to handle problems requiring a variable-rate heat transfer or the superposition effects. A simple graphical technique is used to interpret data with the superposition function. Three approximate solutions, reflecting different time domains, are also presented. These solutions are reliable as long as they are applied within the specified time bounds. Synthetic examples are used to validate the proposed method, and field examples from both oil and geothermal wells demonstrate application of the method.
Reducing Surfactant Adsorption in Carbonate Reservoirs
Authors: Ahmadali Tabatabai , Gonzalez Maria V. , Harwell Jeffrey H. , Scamehorn John F. 
Published: December 2007

SummaryThis paper compares the adsorption of anionic and cationic surfactants on carbonate minerals. It shows that, in general, cationic surfactants may exhibit significantly less adsorption on carbonate minerals than that exhibited by anionic surfactants. It is also shown that cationic surfactant adsorption on carbonates may be reduced dramatically by the presence of divalent cations, an environment in which the precipitation of anionic surfactants might make their use impractical. It is recommended that cationic surfactants be considered for use in miscible flooding with CO2.