bluuebunny/crossref_metadata_2025_split huggingface dataset:
Maintaining Balmoral Field Productivity While Controlling Sand Production with Gravel Packs
Authors: Scrimgeour J. A. , Shepherd C. E. 
Published: December 2007

ABSTRACT
The Balmoral Field is situated 140 miles northeast of Aberdeen in 470' of water. Early well tests indicated the possibility of sand production. To eliminate potential problems with the subsea hardware, it was decided to control sand production with internal gravel packs if target post-pack productivity levels could be met. Trial wells indicated that the target of a Skin less than +25 was achievable by innovatively adapting available technology. Operational results have borne this conclusion out.
Use of Graded Salt Pills in the Montrose Field
Authors: Bennett N. 
Published: December 2007

ABSTRACT
This paper reviews the development of an effective workover fluid system for the Montrose Field, comprising seawater and a graded salt pill bridging agent. The system was developed in response to substantial production impairment associated with earlier workover fluids.
On the Montrose Field, 13 wells are currently being lifted using Electrical Submersible Pumps, with workovers necessary to changeout ESP assemblies when they fail. The reservoir pressures established during field development will not suppport a seawater column. The first workover fluid systems employed seawater and a variety of blocking/ bridging agents such as Hydroxyethyl Cellulose (HEC)/Calcium Carbonate and temperature degradable polymer plugs. These were all unsuccessful, either permanently damaging the wells or being ineffective and allowing excessive seawater losses.
An invert diesel emulsion mud system was utilised for its ability to reduce overbalance and control losses to the formation. However, during the first six months of 1985, workovers on the Montrose resulted in up to a 65% reduction in well productivity. It was believed that mud lost to the formation during the workovers was causing an emulsion block, which was not being removed on return to production.
Since mid-1985, the use of graded salt pills spotted across the perforations with inhibited seawater has resulted in wells being returned to oil production rates greater or equal to the pre-workover rates. Underbalanced reperforating operations have been performed using tubing conveyed guns with the well being re-killed using the same workover fluid system prior to running the ESP completion. With thé seawater/salt pill system no adverse effects to well productivity were experienced.
The number and volume of salt pills required during well killing procedures has been assessed on a well-to-well basis with a view to optimising the pill requirements and reducing rig time. Such optimization should also reduce the clean-up period resulting from a workover. Cost savings of up to $24 per barrel have been realised through use of the graded salt pill system.
Generation of Oil-Wet Model Sandstone Surfaces
Authors: Takach N. E. , Bennett L. B. , Douglas C. B. , Andersen M. A. , Thomas D. C. 
Published: December 2007

ABSTRACT
A technique for modifying the natural water-wetting behavior of clean, dry, Berea sandstone is discussed. The method involves chemically incorporating the vapor of an organosilane onto the surface of the rocks at elevated temperature and reduced pressure. This paper focuses on the first stage of the project, in which the technique was evaluated by silylating quartz plates as sandstone analogs. When the reaction was carried out with quartz at 275 C, strongly oil-wetting surfaces were generated and the wettability was maintained for extended periods of time upon soaking the plates in various liquids. Plates soaked in brine remained oil-wetting for 22 weeks. Altered wettability of plates soaked in toluene or dodecane persisted for 24 weeks. Application of the newly-developed dynamic Wilhelmy plate technique for rapidly and conveniently evaluating the wetting properties of silylated plates is discussed. Using a modification of the procedure described for silylating the quartz plates, we were recently able to prepare samples of strongly oil-wetting Berea sandstone.
The Development of Potassium Cellulosic Polymers and Their Contribution to the Inhibition of Hydratable Clays
Authors: Palumbo S. , Giacca D. , Ferrari M. , Pirovano P. 
Published: December 2007

ABSTRACT
Water-base fluids with inhibitive properties require, as primary components, proper exchangeable ions and effective water soluble polymers; Potassium based drilling fluids formulated with optimized levels of KCl, KOH and water soluble polymers such as sodium carboxymethylcelluloses (CMC), polyanionic celluloses (PAC), partially hydrolized polyacrylamides (PHPA) and modified starches have been investigated by many authors. The field preparation of potassium based drilling fluids generally requires a high level of potassium to counteract the negative effect of sodium on hydratable clays. As a matter of fact nowadays the oilfield industry shows a growing interest in the use of sodium free, potassium based chemicals, examples of which are potassium lignite, potassium asphalt sulphonates and KOH.
This paper introduces a new class of polymers, potassium carboxymethylcellulose and potassium polyanionic cellulose, and demonstrates their contribution to the formulation of inhibitive fluids.
Drilling Fluid Polymer Degradation Studies Using High-Pressure Differential Scanning Calorimetry
Authors: Teeters D. , Kemp N. P. 
Published: December 2007

ABSTRACT
Differential scanning calorimetry (DSC) performed under elevated pressures has been used to study the degradation of starch in aqueous solutions of varying pH. Kinetic parameters associated with starch degradation are presented. This study demonstrates the potential of DSC to easily and inexpensively determine the maximum use temperatures of drilling fluid components under high temperatures and elevated pressures.
New Inorganic Attapulgite Extender Provides Stable Rheology and Supports Heavy Cuttings Even Under Severe Conditions
Authors: Crabb C. R. , Burba J. L. , Holman W. E. 
Published: December 2007

Abstract
An insoluble crystalline inorganic compound has been developed which effectively extends attapulgite in fresh or salt water systems, imparting heretofore unobtainable stability against sedimentation. This novel compound provides a low solids drilling fluid with a variety of desirable properties such as low n value, high temperature stability and a more effective gel structure for carrying or suspending large cuttings. Both laboratory and field test results are given, the latter being in a saturated salt well. The compound shows low toxicity and is easy to apply with conventional equipment.
Miscible Displacements in Heterogeneous Core Systems: Tomographic Confirmation of Flow Mechanisms
Authors: Sorbie K. S. , Wat R. M. S. , Hove A. O. , Nilsen V. , Leknes J. 
Published: December 2007

ABSTRACT
A series of stable and unstable floods has been carried out in a well-characterized, heterogeneous concentric core assembly in order to study predicted recovery mechanisms in such systems. A combination of effluent analysis from the separate layers in the core and computer simulation was used to establish the detailed flows which were subsequently confirmed using computer x-ray tomographic (CT) scanning. Good agreement has been obtained between experiment and theory for unit mobility, and viscous floods in which the respective roles of transverse dispersion and viscous crossflow have been clarified. Some of the main qualitative features found in the unstable displacement (viscous fingering) experiments have also been reproduced using fine grid simulations. CT scanning has been shown to be extremely useful for studying flow mechanisms in systems of this type.
An Experimental Study of the Interactions of Aluminum Citrate Solutions and Silica Sand
Authors: Rocha C. A. , Green D. W. , Willhite G. P. , Michnick M. J. 
Published: December 2007

ABSTRACT
Aluminum retention and the distribution of the retained aluminum on a porous medium significantly affect the location and strength of polyacrylamide/aluminum citrate gels used to selectively reduce the permeability. This study was undertaken to investigate aluminum retention on silica sand when the solid is contacted by aluminum citrate solutions.
Batch experiments were used to investigate the effect of aluminum-to-citrate ratio on aluminum retention and the rate of release of retained aluminum. Displacement experiments with silica sand were conducted in order to investigate the effects of aluminum-to-citrate ratio and displacement rate on aluminum retention, and the effect of pH on aluminum release.
The major findings of this study are that 1) as the aluminum-to-citrate ratio increases, the aluminum retention increases, 2) the amount of aluminum retained by silica sand increases as the displacing rate decreases, 3) the process is reversible, but the rate of aluminum release is considerably slower than the rate of retention, 4) the amount of aluminum released is influenced by the type and pH of the flowing solution, and 5) citrate ions are retained by silica sand primarily as a part of the aluminum citrate complex.
Reserve and Price Security: An Analysis of New Insurance Plans
Authors: David A. , Carson G. P. 
Published: December 2007

ABSTRACT
The energy industry, as any other industry or individual, uses insurance programs to protect itself from general liabilities. The common types of policies for field operations are almost as old as the industry itself, and include, among others, blow-out policies, environmental policies, and plugging and abandonment policies. In addition to general liabilities, the energy industry has always been concerned with minimizing the risk associated with its investments (exploration for oil and gas reserves). In the last several years, the insurance industry has responded to this challenge by offering a variety of risk minimization programs. These are policies that insure financial conditions. However, many were ill conceived and proved a disappointment to policy holders, and in some cases, a disaster to the policy issuers. Not all insurance programs have to be offered by insurance companies. For example, turnkey drilling may be considered insurance against cost overruns. Mesa Petroleum's famous presale of production insured a locked-in level of gross revenue.
Based on the success of the crude futures market and the volatility of oil prices, several groups are now offering programs that insure reservoir production, reserve volume, and/or product price. This paper reviews some of the types of reserve and price insurance programs from the point of view of producers and financial institutions. The interest in these policies is growing among producers as a means of obtaining higher loan value from financial institutions. Do the owners of the policies get more than piece of mind?
Political Risk and Overseas Oil Investment
Authors: Stauffer T. R. 
Published: December 2007

Abstract
Risk of expropriation reduces investors’ expected profit from overseas oil ventures, but possible compensation has little effect. In the event of expropriation, however, the quantum of compensation is intensely contested.
The wide disparity between valuations claimed by governments (net book value) and companies (DCF valuation) can be significantly reconciled. Book value requires certain adjustments, and the "Cinderella effect", the systematic overstatement of value, must be offset.
Indeed, except for windfall profits, net book value and DCF value in general will not differ greatly.
Exploitation of Abu Gharadig (AG) Field, Western Desert, Egypt
Authors: Kenawy F. A. 
Published: December 2007

ABSTRACT
This paper presents the depletion performance during a time span of more than 10 years for the BAHARIYA Reservoir - the major producing horizon of the giant Egyptian gas field: ABU GHARADIG (AG). The paper emphasizes the results of a recent comprehensive geological/engineering study where a detailed volumetric and mass balance analyses were carried out to pinpoint the recoverable reserves under the existing operating conditions.
The results available todate demonstrate that the existing wells will adequately drain the proved gas reserves, and consequently inlet gas compression has to be installed in order to meet the contractual demand-rate and to increase the ultimate gas recovery as well. In addition, the paper offers a brief summary about the gas plant components, the piping system, and the operating methodology.
Application of Impermeable Cement Cement Additive in High Pressure and Easy Lost Circulation Wells and its Operation Technology
Authors: Shuren Tan , Gaodong Shi 
Published: December 2007

Abstract
The primary cementing of a high pressure well occurs a gas - flow quite often in the annulus due to the loss of hydrostatic pressure during the hydration and setting of cement, thus causes the hydrostatic pressure in the annulus to be unable to balance the formation pressure. The result can hardly be estimated of its severity.
This paper presents a study on the mechanism of hydrostatic pressure loss of cement slurry after placement. The experimental study shows that the loss of pressure could be divided into four steps. Furthermore, it is also found that hydrostatic pressure loss will continue even after the cement loses its own weight completely. This phenomenon was evidenced by the fact that the hydrostatic pressure decreases rapidly in the simulated test cylinder and it is named the "negative effect". Study on the process of gas migration into the cement is also presented in this paper. It is obvious that when the formation pressure is higher than the hydrostatic pressure in the annulus, gas will not migrate into the cement and gas flow does not happen either. Because the cement slurry has a certain resistance to the migration or percolation of gas into it, but when the resistance is lower than the gas pressure, the gas will percolate into the cement and result in a gas flow consequently. In order to prevent the gas percolation, it is necessary to increase the internal resistance of the cement until it is equal to or in excess of the formation pressure. Based upon the foregoing understanding, an impermeable cement additive G60 has been developed.
JZ 20-2-10 is a high pressure exploratory well in an oil field in Liaodong Bay of Bohai, China. During drilling, 840 cubic meters mud was lost into the payzone and from it gas kick came several times. When the well was circulated with 1.66 kg/1 mud, the pay zone took mud, but soon after the pump was shut down, the well started to flow. This paper describes the application of a cement additive G60 in cementing the 7″ liner, and the cement bond log and variable density log analyses are given. The cement job was indeed a great success.
Gorilla: A Launch Platform for Space Age From Oil Fields of Harsh Environment
Authors: Shetti B. 
Published: December 2007

ABSTRACT
The object of this paper is to put features of the Gorilla jackup in perspective and see how it can provide following objectives. To provide an improved method for offshore launching of rockets.To provide improved equipment and facilities for space vehicle launch with greater stability and lower cost.To provide an environmentally objection-free launch option.
Case History: Installation of Two Self-Contained Platform Rigs on One Platform-The Planning, Coordination, and Execution
Authors: Parks W. A. , Mooney S. P. , Farag K. F. 
Published: December 2007

ABSTRACT
This report will review the case history installation of two DUAL self-contained drilling rigs on STANDARD OIL's Ewing Bank 826 "A" platform. The early identi-fication of platform - rig interface requirements and limitations has been proven effective in avoiding costly field modifications. Industry wide homogeneity, in the application of API design specifications, is paramount to insured efficient utilization of labor and material resources.
Risk Allocation in a Turnkey Drilling Contract
Authors: Erickson C. R. 
Published: December 2007

ABSTRACT
Turnkey drilling, the drilling of a well for a fixed lump sum price, is steadily gaining acceptance as a viable alternative to having wells drilled on a daywork or footage basis. However, there is considerable lack of understanding on the part of many operators and even some drilling contractors as to the concept of turnkey drilling. As a result there exists a variety of turnkey drilling contracts which are either incomplete in addressing turnkey obligations and risks or overbearing and require the turnkey contractor to assume extraordinary risks.
This paper will delineate and compare the expectations of operators and turnkey drilling contractors relative to the allocation of risk associated with turnkey drilling — what risks the turnkey drilling contractor will and cannot assume and what risks the operators want the drilling contractor to assume. In order to assist the industry in delineating turnkey risks and obligations, the International Association of Drilling Contractors (IADC) has adopted a turnkey contract for land drilling operations and is presently preparing a turnkey contract for offshore drilling operations. The IADC turnkey contracts and principles developed in the IADC daywork1 and footage2 basis contracts will serve as points of reference in examining allocation of risks associated with the turnkey concept.
First Real Time Measurements of Downhole Vibrations, Forces, and Pressures Used To Monitor Directional Drilling Operations
Authors: Cook R. L. , Nicholson J. W. , Sheppard M. C. , Westlake W. 
Published: December 2007

ABSTRACT
A drilling mechanics sub has been developed to measure the dynamic collar forces, accelerations, and fluid pressures just above the bit. These quantities can be transmitted to surface using mud pulse telemetry to provide the driller with real time information about downhole conditions. The measurements have been obtained for the first time on two directional wells in the Gulf of Mexico. On the first well the sub was run in a rotary drilling assembly in the inclined section. On the second well the sub was run behind a steerable system on the build and tangent section of the well. The bending moment measurements gave a detailed description of the well trajectory each time a course correction was made; during jetting operations for the first well, and during oriented and rotary drilling using the steerable motor for the second well. Relatively high transverse acceleration levels were found to be associated with the doglegs of the wells, while relatively low axial acceleration levels were associated with drilling the soft shale formations. The transverse vibrations were shown, for the particular assemblies used, to vary almost linearly with rotary speed for the range studied. However, the transverse vibrations, as well as the bending moment were shown to be sensitive to downhole boundary conditions, especially in open hole sections. On each well measurements were made, at various flow rates, of the differential pressure across the components below the measurement sub; the bit for the first well, and a positive displacement motor plus the bit for the second well. From this data inferences could be drawn concerning pump efficiency and calibration of the downhole weight on bit measurement. In addition, measurement of the differential pressure can be seen as a potential aid in the identification of drillstring washouts, erosion or blocking of nozzles, and bearing wear in downhole motors.
A Rig Adapts to Today's Environment: Improvements in Efficiency and Changes in Cost Structure
Authors: Gensmer R. P. 
Published: December 2007

ABSTRACT
Contractors are in the business of providing the Operator with a product which is a mix of equipment - capacity and willingness to use that capacity, risk-safety of operations and equipment maintenance, and personnel-experience and ability to do what is needed. To continue to provide the most efficient product mix at today's low rates, a Contractor must make adjustments to cost structure. In some cases, these costs can be changed without compromising the product. In fact, a superior product may be the result.
This paper will evaluate a single rig, from 1980 to 1988 with regard to improvements in rig performance, Operator's effective drilling costs, safety, and crew experience level. This evaluation will be presented along with a review of accompanying reductions in cost and changes in daily cost allocation between the categories of maintenance, labor, overhead, depreciation and other contract costs.
Underreamer Improvements for Drilling Moving Salt Formations
Authors: Greener J. M. , Webb D. D. 
Published: December 2007

ABSTRACT
There exists a need in today's industry for a durable, yet versatile, underreamer which will withstand the tortures of hard rock drilling. This paper describes the design, field testing, and subsequent modifications of one such prototype underreamer. The underreamer was utilized, in conjunction with a bi-center polycrystalline diamond bit, to simultaneously drill and underream a fast moving salt formation. Due to the limited success of previously run underreamers, a new tool was designed and built to perform under the severe downhole conditions developed in a drilling/underreaming operation.
Comparisons are made between the prototype underreamer and a similar tool based on body/arm strength and the cutter usage, placement, and durability. Modifications and improvements are documented in a summary of the field tests performed. Recommendations are given to further enhance the performance of the prototype underreamer and expand its applications.
Use of Surface Seismic Data To Predict Formation Pore Pressures (Sand Shale Depositional Environments)
Authors: Weakley R. R. 
Published: December 2007

ABSTRACT
All surface seismic data has velocity information built into it in the way of stacking velocities. From these stacking velocities, estimates of interval velocities can be determined. We have developed a quantitative technique for determining formation pore pressures from the relative changes in these velocities.
From the stacking velocity data, we develop curves which we refer to as ITT (Interval Transit Time) curves. The ITT curves are generated at the proposed location and are correlated to offset location curves to calibrate velocities. Offset location pore pressures are determined and are combined with structural geology to predict anticipated pore pressures of the proposed wellbore. With these curves, in conjunction with geological information to determine structural changes, and offset logs to determine pore pressures in offsets, we can predict pore pressures to be encountered in a proposed wellbore.
To date, we have made such predictions of pore pressure in approximately 20 exploratory wells on the gulf coast prior to their drilling, with excellent results. We will graphically show results on a number of these wells comparing both the mud weights required, as dictated by hole conditions, and the actual pore pressures encountered. Our statistics within Chevron, on the Gulf Coast, indicate that proposed casing programs are adequate for the needs of an exploratory well:
29% of the time if offset casing programs are used,
65% of the time if detailed geological information is used,
&gt;95% of the time if ITT data is also incorporated.
Significant dollars can be saved and increased success in reaching objectives can be realized when pore pressures can be anticipated prior to drilling a well. This technique offers the opportunity to do so.