bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Approach to High Temperature Drilling Fields
Authors: Carney Leroy L. , Meyer Robert L. 
Published: December 2007

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

Abstract
The clay mineral sepiolite has been under investigation since 1972 by our laboratories for possible use in drilling fluids. This paper reviews the work done on this clay mineral in an effort to obtain a drilling fluid capable of withstanding temperatures in the ultra high range. This includes a study on the rheology of sepiolite slurries that have been subjected to temperatures up to 800 deg. F. X-ray diffraction techniques and scanning electron microscope studies were used to examine the crystalline structure of the sepiolite before and after exposure to these high temperatures. There appears to be some changes in the sepiolite after being subjected to temperatures up to 800 deg. F. However, the basic structure seems to be stable. Data is given showing that slurries prepared from sepiolite and other additives have favorable rheological and fluid loss properties over wide temperature ranges. properties over wide temperature ranges

Introduction
Sepiolites belong to a group of magnesian silicates, with a fibrous texture, whose idealized formula can be written Si12Mg8O32nH2O. This mineral is believed to have microporosity, giving it a unique place in the clay mineral family because of its structural characteristics and physics-chemical properties.
Sepiolites derive much of their commercial value from their molecular sized channels and grooves. The channels are lost when the crystals fold, which occurs when the temperatures are elevated and water is driven out of a dry sample of sepiolite. The conditions necessary for folding and the stages and mechanism of this change are only partially understood. Our studies show that when a sepiolite slurry is subjected to elevated temperatures, the channels take on water and swelling occurs.
In our studies of slurries containing sepiolite, it was observed that the rheological properties of the slurries showed a slight increase in viscosity when measured at elevated temperatures and pressures. Due to this apparent temperature stability, formulations containing sepiolite were prepared and tested at these extreme conditions. Parameters that are important for good drilling fluid performance were measured and recorded.

CHARACTERISTICS OF SEPIOLITE AS A CLAY MINERAL
Reports are available on various studies conducted on sepiolite and related clay mineral. Sepiolite deposits and sepiolite/attapulgite deposits have been used in Europe for saltwater clays in drilling muds in lieu of attapulgite normally used in the United States. Oil Companies Materials Association specifications for salt-water drilling clays include sepiolite. At the present time, the API does not recognize sepiolite as a saltwater clay for drilling fluids.
Transient Pressure Analysis for Partially Penetrating Wells in Naturally Fractured Reservoirs
Authors: Bui T. D. , Mamora D. D. , Lee W. J. 
Published: December 2007

Abstract
This paper presents an analytical solution that describes transient pressure behavior of partially-penetrating wells in naturally-fractured reservoirs. The solution is obtained by combining the pseudo-steady state model for naturally fractured reservoirs with the partially-penetrating well model in homogeneous reservoirs. Verification of the analytical solution is made by comparison of pressures derived analytically with those obtained from numerical simulation. The new type curves generated from the analytical solution indicate that partial penetration and double porosity effects cause a characteristic shape of the curves at early and transition time. The type curves may be used to analyze transient well test analysis for partially-penetrating wells in naturally-fractured reservoirs at early and transition time.
Using 3D Seismic To Identify Spatially Variant Fracture Orientation in the Manderson Field
Authors: Gray F. David , Head Kim J. 
Published: December 2007

Abstract
Oil is produced from the Manderson Field, in Big Horn County, Wyoming, from a fracture system with possible significant lateral connectivity. So characterizing the fractures in this field is of great importance. Amplitude Versus Offset (AVO) and Azimuth (AVAZ) analysis of 3D seismic data is used to determine fracture strike and density at well locations in the Manderson 3D. The result of the analysis described in Gray et al (1999) is compared to fracture strike analysis from oriented cores for three wells within the Manderson 3D, to outcrop analogues and to outcrop at the Zeissmann Dome, 10 miles to the SE of Manderson Field.
Using Deltaic Models and Petrophysics of Shales to Find More Permeable Areas in Fields Near the Rockies
Authors: Allen Rob L. 
Published: December 2007

Abstract
Well log sand responses have been routinely used to make maps. However, maps of shale responses can detect and display details about geologic components within sedimentary systems. Additional depositional properties from shales helped to identify and utilize appropriate deltaic analogs. More effective models for locating permeable zones have been created for fields within a large area extending from near the Canadian Rockies to Mexico.
Application of After-Closure Analysis for Improved Fracture Treatment Optimisation: A Cooper Basin Case Study
Authors: Chipperfield Simon T. , Britt Larry K. 
Published: December 2007

Abstract
Fracture stimulation is a technique used to improve production in many oil and gas fields around the world and its application has resulted in significant economic benefit. Further economic gains can be achieved by obtaining both an improved understanding of the reservoir description and enhancing fracture model calibration.
Accurate reservoir description, specifically permeability (k) and permeability thickness (kh), is required for optimising fracture design and execution. As a result, development and/or application of techniques to determine the reservoir description prior to fracture stimulation are of paramount importance. Fracture model calibration, the other major facet of hydraulic fracture optimisation, is achieved by the interpretation of pre-fracture diagnostic injections. Improving the ‘uniqueness’ of these interpretations is thus another key area for enhancement.
With a view to strengthening these two aspects of fracture optimisation and providing measurable economic improvement, After Closure Analysis (ACA) has been studied for its applicability in Cooper Basin tight gas reservoirs by conducting a hindsight evaluation of historical pre-frac "mini-frac" calibration tests.
This paper documents the review of the extensive multidiscipline (completion, stimulation, and reservoir) Cooper Basin database to assess the viability of ACA to determine both reservoir permeability prior to fracture stimulation as well as to improve the uniqueness of pre-frac injection evaluation. Finally, this paper will use the historical perspective of the database review to develop both data collection and application guidelines for ACA.
Experimental Study of Hydraulic Fracture Conductivity Demonstrates the Benefits of Using Proppants
Authors: Fredd C. N. , McConnell S. B. , Boney C. L. , England K. W. 
Published: December 2007

Abstract
Hydraulic fracturing treatments using treated water and very low proppant concentrations ("waterfracs") have been successful in stimulating low-permeability reservoirs. However, the mechanism by which these treatments provide sufficient conductivity is not well understood. To understand the effects of hydraulic fractures on conductivity, a series of laboratory conductivity experiments were performed with hydraulically fractured cores from the East Texas Cotton Valley sandstone formation. Jordan sand and sintered bauxite proppants were used at concentrations of 0, 0.1 and 1.0 lbm/ft2, and the conductivity was measured at effective closure stresses ranging from 1,000 to 7,000 psi.
The results of this study demonstrate that fracture displacement is required for surface asperities to provide residual fracture width and sufficient conductivity in the absence of proppants. However, the conductivity may vary by at least two orders of magnitude depending on formation properties such as the degree of fracture displacement, the size and distribution of asperities, and rock mechanical properties. In the presence of proppants, the conductivity can be proppant or asperity dominated, depending on the proppant concentration, proppant strength and formation properties. Under asperity dominated conditions, the conductivity varies significantly and is difficult to predict. Low concentrations of high-strength proppant reduce the effects of formation properties and provide proppant dominated conductivity. At conventional proppant concentrations, conductivity experiments performed with flat, parallel core faces tend to overestimate the conductivity observed with hydraulic fractures. Actual hydraulic fracture conductivity may be as much as an order of magnitude lower in the presence of low strength proppant. An important implication of this study is that the success of a "waterfrac" treatment is difficult to predict because it will depend significantly on formation properties. This dependence can be overcome by using high strength proppants or proppants at conventional field concentrations.
Water-Rock Interactions in the Pembina Field, Alberta
Authors: Melrose J.C. , Johnson W.F. , George R.A. , Groeneveld H. 
Published: December 2007

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

Abstract
Chemical analyses of produced water samples from the Pembina Field, Alberta, are used to develop new insights relating to water-rock interactions within the reservoir. Samples from areas of the reservoir subjected to extensive flushing with fresh water show that the dilution of formation water is accompanied by a substantial increase in the concentration of NaHCO3. In order to provide an explanation for the NaHCO3 build-up, a simple chemical model of the reservoir has been developed.

Introduction
A description of a polymer pilot flood in the Pembina Field, Alberta, has been given in a previous paper. Chemical analyses of produced water samples from this pilot flood produced water samples from this pilot flood provided evidence for the occurrence of provided evidence for the occurrence of water-rock interactions within the reservoir. The data indicated that the effective salinity of samples from an area of the reservoir subjected to extensive flushing with fresh water is maintained at an equivalent NaCl concentration of about 0.2 percent. A comparison with analyses of produced water samples from other areas of the field has shown that the salinity persistence effect observed in the polymer pilot area is of general occurrence in the pilot area is of general occurrence in the Pembina reservoir. Pembina reservoir. The effect appears to be due in part to the commingling of formation water with the fresh injection water, either within the reservoir or in the producing wellbores. However, the resulting dilution of the formation water is accompanied by a substantial increase in the concentration of NaHCO3. In an attempt to provide an explanation for the NaHCO3 build-up, a simple chemical model of the reservoir has been developed. This model and based on the premise that the pore fluids, both oil and water, will tend to reach chemical equilibrium with all of the mineral phases present in the reservoir. The model predictions are in agreement with the observed relationships between Cl and HCO3 concentrations. This implies that the commingling of formation and injection water may take place primarily within the reservoir.
Maximum Permissible Drillbit Weight from Drillcollars in Inclined (Directional) Boreholes
Authors: Mitchell B.J. 
Published: December 2007

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

Abstract
A discussion of the buckling of drill collars and drillpipe in inclined (directional) boreholes is presented for the purpose of selecting maximum drillbit weights from drill collars such that the section of the drillpipe within the drillstring above the drill collars will not be buckled. The theories of A. Lubinski, R. Hoch, and the work of M. Rollins pertinent to drill-collar applications are pertinent to drill-collar applications are reviewed. The mechanics of drill-collar and drillpipe bending and buckling in inclined boreholes and long-standing misconceptions are discussed. A mathematical equation for the analytical calculation of a maximum permissible drillbit weight from drill collars in inclined (directional) boreholes is derived and presented with solved example problems. A convenient nomograph is given.

Introduction
Drill collars are a major component of the drillstring within the rotary drilling system. They are thick-walled, hollow steel tubes about 30 ft in length with thread connections at either end. A series of drill collars within the drillstring are called a drill-collar string and the common lengths of a string are between 90 and 500 ft. Common wall thicknesses are between 1 and 4 in., which yields linear weights in the range of 20 to 368 lb/ft. The drill-collar string may weigh as much as 100,000 lb. It occupies a position within the drillstring between the drillbit and the drillpipe.
Drill collars were introduced in the Seminole oil fields of Oklahoma in the early 1920's for the purpose of maintaining more vertical boreholes. More vertical boreholes give higher assurance that boreholes will remain within lease boundaries, penetrate the correct location within the geologic structure, and reduce interference between wells during drilling and producing operations.
For three decades the selection of drill-collar strings with respect to their diameters and lengths was an art given to errors arising from misunderstood concepts and misinterpreted experiences. In 1950, Lubinski published his paper, "A Study of the Buckling of Rotary paper, "A Study of the Buckling of Rotary Drilling Strings," which placed drill-collar string selection into the realm of science. His theory is often called the "pendulum theory", or the "one-stabilizer theory" and contends with the problem of analytically aggregating the following variables pertaining to drill collars and the earth's structure:
Full-Scale High-Pressure Stripper/Packer Testing with Wellhead Pressure to 15,000 psi
Authors: Andersen J. N. , Rosine R. S. , Marshall M. 
Published: December 2007

Abstract
The oil and gas field industries continually challenge the limitations of coiled tubing (CT) equipment. With an increasing amount of high-pressure work developing for CT, validating components for this work is a challenge. One component in particular, the stripper element, is of interest. Many manufacturers of tubing strippers rate their components for working pressures from 10,000 to 20,000 psi, but limited test data is available for element wear or resiliency at these pressures.
This paper presents results from full-scale testing of a stripper/packer element at pressures as great as 15,000 psi. Various elements were tested for longevity, internal material integrity, and safety at high to ultrahigh pressures. As a result of the evaluation, (1) the stripper/packer was validated to 15,000 psi, (2) a suitable packing element was developed and tested, and (3) operational guidelines for high-pressure work were developed for the field.
A Hybrid Milling/Jetting Tool - The Safe Solution to Scale Milling
Authors: Eslinger David , Johnson Ashley B. , Mcdonough Aaron , Oettli Mark 
Published: December 2007

Abstract
We present a comprehensive wellbore cleanup toolbox, which combines and optimizes the benefits of jetting, milling and chemical dissolution techniques. The system will clear obstructions from the wellbore and clean back to the tubing wall in a safe non damaging manner.
Conventional cleanup techniques use wash tools, which are inefficient, solvent bullheading which is poorly targeted and wastes reagents or milling tools which can be damaging to the wellbore. These present a less than optimized solution to a commenly occurring problem.
We have developed a tool box which includes an optimized jetting tool for cleaning out soft and weakly consolidated materials. It also presents benefits when used with solvents, or chemical reagents by delivering the fluids directly into the blocking or plugging obstructions with sufficient energy to accelerate the dissolution process and minimize the fluid consumption.
For insoluble materials with a clearance hole we use a self powered jetting tool with the non damaging, Sterling Beads, abrasive system. This will remove scale or other obstructions from the well without damage to the wellbore or jewelry.
For hard and insoluble bridges or plugged wellbores we use a hybrid jetting and milling system. Using a modified PDM with a radial jetting head and small PDC mill. The mill is sized to be smaller than the tool so it cannot contact the tubing or jewelry. Hence the system is safe and non damaging. In addition by using a smaller mill the drilling torque is reduced and the system is more reliable than an equivalent conventional system.
Practical Considerations for Enhancing Coiled Tubing Well Control Operations
Authors: Sas-Jaworsky Alexander 
Published: December 2007

Abstract
Concentric tube well servicing technology is employed in numerous applications where pressure and fluid containment must be controlled at the surface. By design, the primary mechanism for maintaining pressure and fluid containment in these types of concentric-tube services is the purpose-built well control stack working in combination with fluid flow control devices in the surface treatment piping. As such, concentric tube well servicing systems have a unique advantage in that they are not bound by use of balance-weight fluids to maintain pressure and flow control as employed in conventional jointed-pipe rig systems.
However, when service conditions dictate that well pressure be at balance at the surface, well control practices which focus on fluid hydrostatics must be employed. Although based on the processes used in conventional jointed-pipe rig systems, coiled tubing well control practices performed concentric to existing well tubulars are more complex and require greater attention in design and implementation.
This paper provides an overview of the recommended coiled tubing well control stack and flow control device configurations for defined pressure control conditions and offers practical approaches which address the various concerns unique to coiled tubing well control applications.
Optimizing and Managing Coiled Tubing Frac Strings
Authors: Kazakov Serguei , Rispler Keith 
Published: December 2007

Abstract
Multizonal coiled tubing fracturing (CT frac) services have been successfully performed in shallow gas fields in western Canada for more than I year. Properly managing and designing the serviceability of CT strings is critical to these operations.
This paper discusses the practical and theoretical aspects of optimizing the frac-string design, changing the equipment geometry of the CT units, and using a CT fatigue model and fatigue-simulation software. The paper also discusses factors affecting the longevity and performance of frac strings, programs for continuously monitoring the service life of the strings, and actions considered for recovering and extending the fatigue life.
With a properly designed and implemented comprehensive tubing management program, service operators in western Canada have helped ensure a high degree of personnel safety during fracturing while minimizing the risk of CT failure and maximizing pipe life.
A Concept of a New Steerable Drilling System for Coiled Tubing
Authors: Maranuk C. A. , Gaynor T. M. , Chen D. C-K , Pruitt J. 
Published: December 2007

Abstract
Conventional PDM (Positive Displacement Motors) are widely used in coiled tubing drilling jobs. PDC bits are often used with the PDM’s because of their longer life, increased ROP, and increased steerability. But conventional PDM-PDC bit systems often create hole problems and high vibrations that result in casing running problems, downhole equipment failure and lost drilling time.
A new steerable assembly has been designed that provides significant advantages over conventional steerable assemblies. The new system comprises of uniquely designed pin-down mud motor with a specially designed long-gauge PDC bit in a matched drilling system. To date, field results from the new system have shown to improve hole quality and increase ROP. Other advantages include less hole spiraling and tortuosity, reduced vibration, better steerability and hole cleaning, increased bit life, and improved PDM and MWD reliability. These benefits are expected to have considerable implications for coiled tubing drilling applications.
Expandable Wellbore Tubulars
Authors: Stewart R. B. , Marketz F. , Lohbeck W. C. M. , Fischer F. D. , Daves W. , Rammerstorfer F. G. , Böhm H. J. 
Published: December 2007

ABSTRACT
The development of expandable tubular technologies was initiated by the business need to reduce drilling costs, to increase production of tubing constrained wells and to enable operators to access reservoirs that could otherwise not be reached economically without using expandable wellbore tubulars.
Expanded casing applications concentrate on reducing the telescopic profile of well designs. Casings and liners can be expanded against the previous casing/liner in such a way that each time they are set, the well diameter is just reduced by two tubular wall thicknesses. Furthermore, expandable wellbore tubulars also give life to existing wellbores through capabilities for selective water shut-off, damaged casing and tubing repair or for increasing burst and collapse ratings by cladding the inside of casing and tubing.
Yard tests have shown that it is possible to expand tubulars by up to 40 pct in diameter at a rate of up to 100 [ft/min] by means of propelling ceramic headed or hardened steel mandrels. The critical success factors for unconstrained expansion and cladding of wellbore tubulars and their implications for downhole applications will be addressed.
The development of commercial products for use in the oil-field requires the complementary capabilities of both service and operating company personnel. A novel type of technology commercialization concept has been established to provide the technology to the Industry through two fifty-fifty joint venture companies between an operator and major service companies.