bluuebunny/crossref_metadata_2025 huggingface dataset:
Environmental, Health, and Safety Decision Making for Naturally Occurring Radioactive Materials in Producing Operations Using Pathway Exposure Analysis
Authors: Miller H. T. , Bruce E. D. , Cook L. M.
Published: December 2007

A number of health and safety issues have arisen because of the occurrence of NORM, naturally occurring radioactive materials of the 226 radium and 228 radium decay chains, in production operations. Issues such as risk to workers or the general public, disposal of contaminated production fluids, disposal of NORM removed in cleaning equipment and tubing, and procedures to follow in well rework, equipment decontamination and other types of maintenance must be addressed.

This paper describes the application of a procedural aid to decision making known as PATHWAY EXPOSURE ANALYSIS to these issues. The procedure examines the radiation exposure of individuals and population groups by calculating the dose from each exposure route and pathway. The sum of these is used to calculate the overall risk to the individual or the group. This method can be used to examine managementand procedural options to identify the option offering the smallest risk. Risk information coupled with cost estimates then permits management maximum utilization of its available resources.

Three uses of Pathway Exposure Analysis will be discussed. The first will be a description of the identification of environmentally Sound disposal or remediationoptions for production sites. The secondwill be a description of how Pathway Exposure Analysis can be usedto determine acceptable water limits for a specific classor use of surface waters. The third will demonstrate how this method can be used to reconstruct employee dose.

International Commission on Radiation Protection and U.S. Environmental Protection Agency dose conversion and dose weighing factors are used to calculate individual exposure. Results are presented in the form of dose to the maximum exposed individual and, where appropriate, as the average exposure to the exposed population.
Naturally Occurring Radioactive Materials (NORM) in the Oil and Gas Industry: A New Management Challenge
Authors: Grice K. J.
Published: December 2007

This paper will attempt to explain some of the mystery associated with Naturally Occurring Radioactive Materials (NORM) by describing what NORM is; how it is associated with oil and gas; what problems NORM may present; how it can be measured; and what current and pending regulations may affect how NORM contaminated equipment and soil can be handled. Unfortunately, at the present time the answers to the last item are by no means definitive. In fact, the answers in dealing with NORM will be an evolutionary process shaped by regulatory agencies, industry and the public. But first, let's discuss what NORM is.

Naturally Occurring Radioactive Materials, otherwise known as NORM, represent a wide range of radioactive isotopes, including such elements as carbon 14 and potassium 40. Both of which are present in the human body. However, the main radioactive elements of concern in oil and gas production are those found throughout the earths crust and specifically are present in the formations from which oil and gas are produced. These elements include Uranium and Thorium and their respective daughter products including Radon gas. Yes, this is the same radon gas that may be present in your home and is receiving all the attention from the media and the Environmental Protection Agency (EPA) as a leading cause of lung cancer deaths. The presence of these materials in oil and gas operations has been known practically since we first learned about radioactive materials. However, it was not until the early 1980's that NORM became recognized as a potential problem. To see where we are today with the NORM issue, it's a good idea to look at the beginning.
Marine Mammals and Seismic Research in the Dutch Continental Shelf
Authors: van Dessel J. P.
Published: December 2007

In recent years, interest and concern for marine mammals (seals, dolphins and whales) particular on the Dutch continental shelf has greatly increased. These concerns have led the Dutch Government to consider banning seismic research in the Dutch Continental Shelf during the period April to October, with effect from 1991. Seismic research is intensive during the sunnier sccson because current methods depend on good weather conditions.

The importance of the environment, as well as the interest of the E&P industrie in the Dutch Continental Shelf, demand careful consideration of this problem. Four aspects need consideration:

– the presence or absence of marine mammals, – seismic research techniques, – the interaction between both of the above, – the effectiveness of protective measures.

In the following sections, the occurrence of marine mammals in the Dutch Continental Shelf, the ecology of the various species, the developement and current status of seismic research and the effect of such seismic investigations upon marine mammals are discussed. Conclusions are drawn in Section 5 concerning the necessity and effectiveness of the proposed ban. Likewise, recommendations have been made in Section 6 on a possible course of action .
Optimal Environmental Strategies: Fit for Exploration
Authors: Wright N. H.
Published: December 2007

Reductions in the environmental impact of exploration seismic can be achieved through improved planning from the scouting stage to post abandonment, environmental screening, EIA's geared to direct implementation of prevention and control measures, specifications in contracts and verification in the field through impact measurement and recording by supervisors.
Environmental Auditing of Government Administration Systems for the Petroleum Industry
Authors: Hughes H. R.
Published: December 2007

New Zealand's Parliamentary Commissioner for the Environment has an environmental auditing role for reviewing government systems that manage the allocation, use and preservation of petroleum reserves and the performance of public authorities in implementing the systems.

The functions and powers of the Commissioner under the Environment Act are explained.

The Commissioner has audited proposals for a new offshore gas platform and has reviewed current administrative arrangements for dealing with oil spills. In carrying out these investigations a number of deficiencies in government policies and legislation were noted.

A lack of criteria whereby governments make decisions on resource allocations is of concern. Government responsibility for policy decisions which address the effects of petroleum extraction and use needs to be made explicit so that effective planning for exploration and production can take place. The desirability of governments, rather than the industry, setting depletion rates is discussed.

A fragmentation of responsibility between central government, local government and the industry, together with a lack of resources, had disadvantaged effective planning for preventing and containing oil spills in New Zealand.

These issues are discussed with respect to where responsibility should lie and where legislative and regulatory control are desirable.

Communication and cooperation between all affected groups including the public is an important aspect of effective environmental planning and management by public authorities. Advice from the Commissioner on how environmental administration could be improved is identified.
The Environment: Its Cultural Importance
Authors: Reynolds G. J.
Published: December 2007

This paper presents a view of the differing values placed on our natural environment as a result of cultural background. It compares the attitudes and actions of technically developed consumer societies with those which are closer to nature and more dependant on their environment for survival. Finally it identifies the issues which must be considered by exploration and production companies operating in these sensitive areas.
Employee Assistance Programs in the Upstream Petroleum Industry: A Canadian Perspective
Authors: Crutcher R. A. , Yip R. Y. , Young M. R.
Published: December 2007

This paper is a descriptive overview of Employee Assistance Programs (EAPs) in the upstream Canadian petroleum industry. The authors review current EAP models within the occupational health setting and the Canadian health care context This article also explores the challenging issues of EAP's emergent functions in workplace substance abuse programs, its changing role in organizational effectiveness and its professional identity.
Psychosocial Aspects of the Offshore Oil Industry
Authors: Sutherland K. M. , Flin R. H.
Published: December 2007

The British sector of the North Sea oil and gas industry currently employs over 30,000 individuals on drilling rigs, production platforms and support vessels, yet very little is known about the psychological demands of this work environment. This paper describes a research project designed to examine some of the psychological and social aspects of offshore working life. Three operating companies and one contracting company participated in the study which involved a series of interviews followed by a questionnaire survey designed to collect information on demographic factors, Type A behaviour pattern, sources of stress, job satisfaction, physical and mental health.
Safety as an Integrated Part of Platform Design
Authors: Harstad E.
Published: December 2007

Traditionally, risk, and safety analyses have been carried out as separate activities relative to the conceptual and detailed design development of offshore installations.

By continuous involvement from safety specialists, applying analytical tools as well as experience from former studies, it can be assured that –the correct decisions with respect to safety can be taken and incorporated without causing significant cost increase or schedule delays;–the need for additional compensating safety measures due to lack of inherent safe design is minimised;–the amount of redesign and reconstruction activities for safety reasons can be kept to a minimum.

This paper addresses how safety studies can be incorporated into the project organisation and project schedule, and the timing and type of qualitative and quantitative safety studies during the various phases of a project development.

Examples of application of risk and consequence studies as active design tools in recent developments are given.
Horizontal Well Evaluation in a Giant Oil-Rim in Unconsolidated Sand
Authors: Oosten R. K. V. , Cliff W. J.
Published: December 2007

This paper concentrates on experience gained and techniques currently used in the evaluation of horizontal wells in an oil-rim located in the unconsolidated sands of the Rabi field, onshore Gabon, West Africa. Valuable experience leading to improved understanding has been obtained in the areas of:

– Open Hole Logging, including Fault detection and (Wireline) Formation testing – Production Logging on Coiled Tubing, including the use of Pulsed Neutron logs to identify gas and water in the horizontal section – Downhole pressure measurement for understanding horizontal well ‘dynamics’ and for production optimisation – Horizontal well test interpretation in a compartmentalised oil-rim.
Sizing an Electrical Submersible Pump in a Solution-Gas-Drive Horizontal Well
Authors: Kallas P. A.
Published: December 2007

A model has been developed to optimize sizing the staging and brake horsepower requirements for an electrical sub-mersible pump (ESP) in a solution-gas-drive horizontal well. Three components are examined by the model, reservoir in-flow performance, casing and tubing outflow performance, and pump performance. Since severe gas slugging has been a characteristic of many horizontal wells, the gas slugging potential is monitored during the pressure traverse from where the fluid flows into the wellbore to the pump set depth. Flexibility for handling the gas at the pump intake has been included. The model can take into account the gas removed by a gas separator and the gas produced up the annulus. Actual data provided from norizontal wells producing with electrical submersible pumps has been used to verify the model's relative accuracy in sizing.
Multi-Rate Test Evaluation Using Field Cases
Authors: Pacheco E. , Da Prat G.
Published: December 2007

In this work, a brief summary is presented on the fundamental principles of multirate testing. The main objective is the analysis of several field cases where the technique has been successfully in the determination of drainage area reserves. The method of solution is presented for pressure transient analysis and involves the use of a numerical simulator in most of the cases for an optimum reservoir modeling. Examples of tests conducted in the Maracaibo Lake fields are presented. Based on several field cases, an efficient design of the multirate test in order to get the reservoir evaluation objectives was obtained. An extended flow rate period was added to the conventional way to conduct these tests resulting in a better reservoir description for the drainage area investigated. The results were used to determine the next development well in the field under study.
Porosity and Permeability from SEM Based Image Analysis of Core Material
Authors: Bonnie J. H. M. , Fens T. W.
Published: December 2007

Investigations into the relationship between the microstructure of reservoir rock and its petrophysical properties have made it possible to develop new procedures for deriving porosity and permeability data from digitised images of rock samples. The images of highly polished, resin-impregnated rock samples are recorded with an integrated scanning electron microscope/image analyser facility. Geometrical and topological features in the images have been quantified with the image analyser for 62 rock samples from 13 different reservoirs. Image-derived properties were compared with petrophysical properties as determined on corresponding core plugs using conventional analytical techniques.

The image-derived data pertain to a section through each sample and are therefore essentially two-dimensional. A number of quantities, such as porosity and surface-to-volume ratio, are determined from these data using stereological procedures. The subsequent analysis establishes a relation between image-derived quantities and plug-derived permeability.

The results obtained so far indicate that the image-derived porosity agrees with the core-plug-derived value to within 2.5 porosity per cent, while permeability is reproduced within a factor of 2.5. Deviations are ascribed partly to plug heterogeneities. The permeability relation has been tested on a challenging data set consisting of 16 additional samples, not in the above-mentioned learning set. The results show a major improvement over the conventional porosity-permeability cross-plot.
SIC - System for Identifying Contaminants in Drilling Fluids
Authors: Barragan R. V. , Aragao A. F. , Machado J. C.
Published: December 2007

Preventive treatments are the best method to avoid contamination. However, if it occurs, it is necessary to restore the original properties off drilling fluid by addition of chemicals after the contamination. The changes in the drilling fluids properties, determined by regular test at specified intervals, will indicate the type and degree of contamination and required treatment.

This paper presents a software which identifies various contaminants from the analysis of their properties during drilling operations.

A TURBO PASCAL program was developed using some artificial inteligence techniques. This program, named SIC (System for Identifying Contaminants), verifies, for each usual contaminant, the possibility of its degree of influence on each drilling fluid property.
Control of Erosion - Corrosion in Flowlines of Wells in Northern Monagas
Authors: Serrano J. , Peñalver J.
Published: December 2007

This paper presents the results of erosion-corrosion studies on 31 flowlines of wells in Northern Monagas, based on ultrasonic measurements of wall thickness of 4 1/2" diameter sections, extending from the wellhead standpipe to the anchor pile. These sections showed wear in the range of 12.5 to 35% with respect to nominal thickness of 11.12 mm and 8.55 mm, which correspond to critical erosion-corrosion rates of 3.7 to 12.88 mm/year and estimated remaining useful lifetime of 4 to 19 months before the onset of failure.

Subsequent inspections, which included cutting open the critical sections facilitated verification of the degree of wear which had taken place. From these results, a program was developed for the replacement of damaged short radius, 4" diameter, 45° elbows, by large radius, 6" diameter, 45° elbows and replacing the 4 1/2" diameter pipes by 6 5/8" pipe. These changes resulted in a decrease in the erosion-corrosion rate to approximately 0.26 mm/year and an increase in the estimated useful life of the most critical lines from one to as much as eigth years.

The results of this work also indicated that the equation Er = KVn (where Er is the erosion-corrosion rate, V is the flow velocity and n and k are constants) which was found by other workers to be applicable to erosion caused by aqueous References and illustrations at end of paper. slurries in laboratory studies, can also be used to describe the erosion-corrosion processes under actual operational conditions of producing wells.
Drilling Mud Solids Control and Waste Management
Authors: Bouse E. E. , Carrasquero J. E.
Published: December 2007

Several of the processes used to reduce the environmental impact of drilling are counter—productive. They can increase drilling cost and often worsen the waste disposal problem rather than solving or relieving it. Two-stage centrifugation is probably the worst of these processes. The trends toward total reliance on shale shakers for solids control, and the return of the liquid portion of hydroclone underflow to the system, in unweighted muds, are also very troublesome.

This paper reviews the importance of solids control and its relevance to waste management, discusses closed mud systems and other methods of handling drilling fluid waste, and reviews the proper design, installation, and monitoring of the solids removal system.
Dual Completions in EI Furrial Field
Authors: Mayol J. R. , Asuaje R. , Salazar A.
Published: December 2007

The "EL FURRIAL" field has an extent of 31250 acres, in which the original oil in place of medium API gravity oil is in the order of 4000×10 Bls. The main reserves are in the naricual formation. In this zone there are three reservoirs, in the following order: upper naricual, medium naricual and lower naricual, the production of these zones have been planned for the extraction of proportional volumes from each reservoir in order to optimize drainage while maintaining equilibrium of pressure and production in the reservoir. The configuration of the naricual formation establishes a favorable condition for dual completions.

In order to design the optimun dual completion to be run in the area, we conducted an engineering study taking into account the latest technology available worldwide on this type of completions. The experience gained by Lagoven running 176 dual completions for the past 30 years in Western Venezuela using double grip hydraulic dual packers. Proved to be very difficult to retrieve from the well-during the workover operation.

Based on these reasons, on march of 1988, we began a program to complete a well with two production strings consisting of 3-1/2"×3-l/2" (8,9 × 8,9 cm) using a dual flow assembly, instead of double grip hydraulic dual packers.

This reccomendation was applied successfully in the furrial No. 12 well; and until august 1991, we have run 17 dual completions in this field averaging a daily production of more than 200.000 BOPD of medium API gravity oil.

The objective of this paper is to present the experiences and results gained using this technique to complete in deep, high pressure and high temperature wells.
The Influence of Capillary Pressure when Determining Relative Permeability from Unsteady-State Corefloods
Authors: Savioli G. B. , Bidner M. S. , Grattoni C. A.
Published: December 2007

An automatic history-matching algorithm has been developed to determine relative permeabilities and capillary pressure curves simultaneously from the production history of a displacement test of oil and water through a core. Relative permeability and capillary pressure curves are represented by power functions. Those representations contain some parameters which are found by minimizing an objective function. The objective function is formed by the sum of the square of the differences between experimentally measured and numerically simulated production data. The numerical simulator is an IMPES finite-difference program which models the one dimensional two-phase flow. The minimization is performed by a non-linear regression algorithm: the Quasi-Newton Approximation for the Least-Squares Problem (Broyden-Fletcher-Goldfarb-Shanno formulae).

The automatic history Bitching algorithm is applied to analyze the influence of capillary pressure on the determination of relative permeability curves. The algorithm is tested with simulated data and with actual experimental data.

Database consisting of simulated experiments with random errors are tested to demonstrate the feasibility of the method. Besides, they provide exact relative permeability curves for comparison purposes. In effect, results obtained by using simulated data show the convergence and uniqueness of the algorithm. But the main observation is that relative permeabilities estimates can be in error when capillary pressure terms are neglected.

Several sets of actual experimental data at inlet constant pressure are also tested. Convergent solutions are always found. Three different objective functions are applied. They are formed by oil rates, total fluid rates or a combination of both. The solution is dependent on the chosen objective function. Best adjustments are found by applying a combination of oil and total fluid rates, and including capillary pressure.
Fully Implicit Compositional Modelling of Gas Condensate and Volatile Oil Reservoirs
Authors: Gomes Hamilton P. , Corrêa Antonio Cláudio F.
Published: December 2007

This work describes an isothermal and two-dimensional fully implicit compositonal model, which has been developed to the modelling of retrograde gas condensate and volatile oil reservoirs.

The model considers oil, gas and water phases, and may be used with either cartesian (x-y) or cylindrical (r-z) grids. Water has been considered to be immobile and slightly compressible, and water saturation is a function of pressure. Instantaneous thermodynamic equilibrium has also been considered, with no water dissolved in the hydrocarbon phases and no hydrocarbon dissolved in the water phase. Fluid-rock iteractions have not been considered.

Phase equilibrium and fluid properties have been computed by means of the Peng-Robinson6 equation of state. The adjustable coefficients of the equation of state have been previously determined by means of a comercial PVT simulator.

The resulting system of partial differential equations has been discretized by the finite difference method, yielding a non-linear system of algebraic equations. The one-point upwind scheme has been selected to compute the molar densities and the saturation dependent properties.

The Newton-Raphson method has been selected to solve the resulting non-linear numerical problem. The block penta-diagonal matrix has been solved by Gaussian elimination, which takes advantage of the matrix sparcity. The grid-block saturation pressures are updated at the end of each timestep.

Due to the problem complexity, the validation of the model has been provided to the steady-state flow case, which presents a known analytical solution for compositions and saturations.

Examples of application of the computer model to depletion process and well testing are presented.
Influence of Mass Transfer in Bottomhole Pressure and Afterflow Determination from Fluid Level Data
Authors: Pires José A. P. , Corrêa Antonio Cláudio F.
Published: December 2007

The Acoustic Well Sounding (AWS) method can be used for indirectly computing both bottomhole pressure (BHP) and rate of afterflow in pumping wells. This calculation uses fluid level and casinghead pressure data obtained during a a transient test. During pressure buildup tests, free gas goes back into solution as the pressure increases in the wellbore. This causes a reduction in both oil density and free gas flow rate. Mass transfer between the oil and gas phases has not been explicitly considered in the literature. This can be of significant influence for long shutin time. In this paper a method is proposed which accounts for the mass transfer between liquid and gas phases. A selected comparison example from the literature has been interpretated using both conventional and rate deconvolution analysis.
An Integrated Approach to the Design and Interpretation of Reservoir Tests and Well Productivity Analysis
Authors: Burgess K. A. , Pelissier-Combescure J. , Joseph J.
Published: December 2007

One important goal in reservoir testing is to determine the reservoir characteristics and the well's productivity. Measurements which can contribute to this goal include well logging, fluid sampling, pressure transient testing, and production profiling. A careful analysis of these measured data will provide adequate information for well evaluation. The purpose of this paper is to show how an integrated reservoir testing methodology in conjunction with a human engineered procedure on computer enhances the reservoir characterization and the evaluation of well performance.

This integrated methodology includes concepts, which have been implemented in recent approaches to reservoir testing and NODAL* analysis. During the design phase of each test, sensitivity studies provide insights that facilitate adequate data gathering for valid interpretation, which can help minimize the cost of the test. During interpretation, the central issue is to identify a realistic reservoir model which reflects the transient pressure and rate behavior. Here significant use is made of the log-log plot of pressure change and its derivative with respect to superposition time. Systematic diagnosis of the log-log plot helps identify different flow regimes, while specialized plots and type curve analysis provide a basis for the estimation of reservoir parameters. Lastly, the computed results can be easily integrated into a NODAL analysis to study and evaluate the well's productivity.

The examples presented illustrate the benefits of a systematic approach to reserovir test design and interpretation, and well productivity evaluation. The computer procedure also has the advantage of incorporating input data from several sources, including openhole logs and the Repeat Formation Tester (RFT*) tool.
A Study of Rheological Properties of Non-Newtonian Fluids and Settling Behavior of Ceramic Proppants Manufactured in Louisiana, USA.
Authors: Alcócer C. F. , Ghalambor A. , Sweet L. H.
Published: December 2007

This paper presents the results of the study of the settling rate performed on C-P, C-L Proppants, and Sand for 16 and 20 mesh sizes.

The method of experimentation was Stoke's Method which is used for analysis; the Stoke's Law was not applied to the measurements. This is due to the fact that the Stoke's Law applies only to measurements of in newtonian fluids. The polymer (nonNewtonian fluid) used XCD is a shear thinning fluid with gel behavior and its viscosity is depended upon the fluid motion.

The test performed in a settling tube simulates static fluid condition. The results showed the effects of proppant density, diameter and size of particles, as described by Stoke's Law. The proppant C-P has 2.2 to 2.5 times the velocity of the proppant C-L. Proppants of size 16 mesh have 3.2 to 3.6 times the velocity of 20 mesh proppants. The first shows the effect of the density and the second illustrates the size or diameter effects, respectively.
Diffusivity Equation for Real Liquids with Gas in Solution
Authors: Lanfranchi E.
Published: December 2007

A rather comprehensive theory has been developed to describe fluid flow phenomena in porous media. This theory, under the constraints of appropriate simplifying assumptions, ultimately leads to expressions which enable the petroleum engineer to characterize reservoir behaviour. In this context, one frequently treats some form of the diffusivity equation in conjunction with data obtained from well tests to arrive at specific reservoir parameters. For example, so-called pressure transient analysis can be used to arrive at estimates of the formation thickness permeability product, the storage capacity, the average reservoir pressure, etc. For liquid flow, the technique involves reducing the diffusivity equation to a form where pressure becomes the independent variable. This requires the assumptions that the liquid is both, ideal and slightly compressible.

In this work it has been developed an alternative approach which does not depend upon the assumptions cited above. An additional intent is to investigate the effects of these suppositions on computed pressure distributions in a one-dimensional system.
Utilization of Water Salinity as a Continuous Miscible Tracer in Waterflooding
Authors: Angeles R. Martínez
Published: December 2007

An experimental simulation on the miscible displacement in fractured oil reservoir is presented. The theoretical and experimental studies are based on the ideas originally developed by Coats and Smith and recently modified by Perez-Cardenas in connection with miscible and immiscible displacements in heterogenous media which contain a double-porosity system. The proposed model considers that fluid displacement takes place through the fracture system by Convection-Dispersion process, while the matrix blocks exchange matter with the fractures mainly by hydrodynamic dispersion and molecular diffusion. To test the theory and experimental model, several displacements simulations were carried out with real field data. This paper describes application of two-dimensions simulations to miscible displacement during waterflooding operations. The first section describes a method of calculating the behavior of a water salinity tracer by use of an analytical solution for the Dispersion-Convection Equation. The second section of this work extends the analytical results in Berea sand cores. Finally, the last section covers the field simulation, thus the objective is to study the tracer evolution for frontal displacement simulation. Results are presented on calculations of salinity digital images for each evolution step at several pore volume injected and levels of mechanical dispersion-convection.
Reserves Nomenclature World-Wide: an Utopia?
Authors: Martinez A. R.
Published: December 2007

Everybody, everywhere acknowledges the need and usefulness of a simple, unassailable nomenclature for a hydrocarbons reserves system with world-wide approval; non-geological and non-engineering considerations, prominently of a commercial character, have prevented the acceptance of such a global scheme. Most relevant to the proper review of the awkward situation, is the prerequisite recognition of reserves as physical entities of L3 dimension.

Reserves are the quantities recoverable from the underground hydrocarbon deposits. No individually recommended scheme of reserves nomenclature seems to have the necessary persuasive power nor absolute imagination to develop into a universal classification; only, international organisations of undisputed prestige could submit a system capable of a general agreement, intelligible to economists, policymakers, politicians and laymen, while at the same time satisfying the professional needs of the petroleum scientists and technologists. The objective should be to incorporate existing definitions and nomenclatures, to those currently used in legislation and banking, or trade and custom. Particular positions of countries should be set aside, towards attainment of an international consensus. Then, a visionary utopian reality shall prevail, for a perfect technical order.

These devices be then made laws. Thomas More, Utopia, 344.
Heat Checking/Quench Cracking Tool Joints
Authors: Altermann J. A. , Smith T. B.
Published: December 2007

Tool joints may be heated in service above the critical temperature of steel through the heat of friction. When this steel is quenched by the drilling mud, longitudinal cracks develop. These initially shallow cracks propagate rapidly. In boxes they lead to washouts near the makeup shoulders. In pins, some cases have lead to pin base failures and fishing jobs.

This drill string problem has plagued the oilfield for more than 40 years. In spite of this, many experienced drillers are unaware of its existence and have difficulty accepting the facts when they are first presented.

Heat checking/quench cracking of tool joints may occur when they are forced against the wall as they are rotated or pulled from the hole. This force or side thrust may result from an intentionally deviated well or from one which developed a severe dogleg.

The effects of severe in-hole heating has recently been observed on bottom hole assembly components used with top drive systems.
The Design Approach, Operational Performance, and Future Prospects for Self-Erecting Semisubmersible Tender Drilling
Authors: Nagel M. E. , Knecht H. I. , Jackson M. L.
Published: December 2007

Tender assisted drilling is an old concept finding a new following. The search for more cost effective methods for platform drilling has lead to a reevaluation of tender drilling. This paper presents a description of a successful design, the design philosophy of the system, a performance review of the system and future prospects for the concept.

Niche marketing is not uncommon to the contract drilling industry. The wide variation in offshore drilling equipment capabilities available to operators indicate clearly that unique solutions have been developed in response to niche market requirements. Rigs categorized by environmental capabilities, drilling depth capabilities, drilling program duration, platform size and space limitations and myriad others have been developed. The semisubmersible tender is, in this respect, merely another such concept, but for what niche?

Operators having older platforms with limited deck space available for a full sized platform rig wanting to drill for new or deeper horizons is an obvious application. The Derrick Equipment Set (DES) which is placed on the platform extends roughly 21 to 30 feet from the well center in directions typically critical to arrangement of packages. This minimizes platform real estate required to perform drilling operations.
Long-Reach, High-Angle Drilling in the Gulf of Mexico: A Case History of Eugene Island Block 370 Well B-11
Authors: Gadberry R. L. , Switzer S. S.
Published: December 2007

NERCO Oil and Gas, Inc. recently drilled and completed its first high angle, extended reach well in the Gulf of Mexico from Eugene Island Block 371. The field is located approximately 85 miles offshore Louisiana in the continental slope Pleistocene producing trend (Fig. 1). The platform is located in 420′ of water and currently produces gas from the 12 slot facility. E1 370 B-11 was drilled to a measured depth of 8958′ MD and a vertical subsea depth of 3000′. Horizontal displacement was 7358′ resulting in a horizontal displacement to vertical depth ratio of 2.45. Maximum angle reached was 90.75 degrees.
First Field Trial of a Coiled Tubing for Exploration Drilling
Authors: Traonmilin E. M. , Courteille J-M. , Bergerot J-L. , Reysset J-L. , Laffiche J-M. Y.
Published: December 2007

Within the scope of comprehensive efforts to reduce the cost of exploration drilling, Elf Aquitaine has performed with Dowell Schlumberger a first trial of open-hole coiled tubing drilling in the Paris Basin. The purpose of this trial was to determine the feasibility of using coiled tubing drilling units instead of conventional rotary rigs to drill slim hole exploration wells. The feasibility has been verified and applies to some specific prospects. A second trial is planned in 1992 in the same basin.
Design and Implementation of a Bulk Mud Additive System to Reduce Personnel Exposure and Eliminate Waste
Authors: Wisnie A. P. , Brazzel Ron
Published: December 2007

In an effort to limit personnel exposure to oilfield chemicals and simultaneously reduce environmental waste, a bulk additive system was designed and installed for handling drilling mud products on a recent drilling project. Although some problems were initially encountered, the system was modified to completely fulfill its objectives. Both occupational safety risks and environmental wastes were significantly reduced. Efforts are currently being made to improve the ease-of-use of this system for future drilling projects.
On the Stability of Shales and Its Consequences in Terms of Swelling and Wellbore Stability
Authors: Santarelli F. J. , Aquitaine Elf , Chenevert M. E. , Osisanya S. O.
Published: December 2007

Recent experimental studies have shown that shales are able to transfer both mass and pressure. Consequently, they are permeable media even though their permeabilities are extremely small.

A series of free expansion tests on shales contacted by various aqueous fluids under high pressure and temperature is analysed in the light of this basic result. It is shown that a strong coupling exists between shale swelling and permeability as clay minerals expansion impairs permeability by at least one and may be two orders of magnitude. Swelling affects therefore the wellbore wall but cannot propagate deep inside the rock. It is also shown that the more inhibited the fluid is, the more permeable the rock remains.

Furthermore careful geochemical analysis show that the water front movement inside the rock is in competition with an ion counterflow. The data suggest that temperature is a major parameter in increasing the rate of such flows.

In the final part of the paper, the consequences of these results are analysed in terms of wellbore stability and it is shown that they form an excellent framework to explain the delayed failures in shales which are commonly encountered in the field.
Dielectric Constant Measurements: A New, Rapid Method To Characterize Shale at the Wellsite
Authors: Leung P. K. , Steiger R. P.
Published: December 2007

Hydratable shales often lead to a variety of drilling problems such as, wellbore instability, stuck pipe, and solids buildup in drilling fluids. It is important that a timely measure of hydratable clay content in shale formations be available during drilling so that appropriate action can be taken to minimize their detrimental effects. A new dielectric constant measurement (DCM) technique was developed to allow rapid, quantitative determination of shale properties at the wellsite, using a small sample of cuttings. Specific surface area is a measure of the total hydratable surface in a rock and is dominated by the hydratable smectite clay present. The dielectric constant for a shale is also strongly influenced by the presence of hydratable clays and can be correlated with specific surface area. A dielectric constant to surface area correlation was developed based on tests on hundreds of cuttings samples from many wells from around the world and thus shale surface areas can be obtained from DCM data. The wellsite DCM test is run with an inexpensive, portable test kit. Field tests on several Exxon wells showed that DCM data can be collected routinely on-site by the mud logger. This paper introduces the wellsite DCM test procedure and presents field results.
Industry Participation in the Development of an Integrated Drilling Engineering Applications Platform
Authors: Sawaryn S. J. , Grayson H. L.
Published: December 2007

In 1990, BP Exploration with EXLOG, Inc. commenced work on the development of a new drilling information system to support current and future drilling engineering applications.

A formal structured analysis and design methodology was employed successfully to develop a model of the drilling business, which was then used to establish the system's requirements. Information was provided by a wide range of representatives from various disciplines worldwide. The formal analysis, conducted in this way provides a sound basis for the development and future evolution of the system, though it is costly and cannot be entirely objective. Work has now commenced on the construction of the system.
The Designing and Building of an All-Purpose Automatic Torque-Wrenching Machine for Drilling Rigs
Authors: Kinzel Holger , Pietras B. G.
Published: December 2007

Drilling rig automation is one of the key issues for the future of safe and economic drilling operations. Tripping, as well as casing and tubing running operations, represent the considerable amount of total rig time of more than 30%. These operations incorporate the risk of possible accidents due to the manual work involved.

A hydraulic automated torque wrenching machine was developed which is capable of spinning and making up a full range of drillstring components as well as tubing and casing connections in a diameter range between 2 3/8″ and 21″. This wide size range in connection with the high torque values of up to 190,000 Nm (140,000 ft lbs) called for new concepts and developments, which are described. The full integration of this automated torque wrenching machine into an automated drilling process includes a computer based joint analyzed makeup system.
Cementing as a Total Service
Authors: Stilley R. D. , Griffith J. E.
Published: December 2007

Economic realities and an increasing emphasis on quality improvement and quality management have prompted a re-evaluation of the relationship between service companies and operators or drilling contractors and the ways in which they interact to perform oil and gas well cement jobs. The authors believe that on a global basis, drillers and producers would benefit from forming partnerships with service companies wherein more responsibility for the cementing operation is passed to the service company to plan and execute the work.

Using this approach, the service company would manage all aspects of the cementing program from planning prior to spudding the well through to production or abandonment.

Precedents for this type of partnership have been set by cooperative actions between service companies and operators in the past, such as (1) joint research projects, (2) interdisciplinary problem solving teams, (3) joint introduction and testing of new technologies, and (4) turnkey operations.

Potential benefits to the operator include the following:

Improved quality and improved results can be expected, and the quality of service would be uniform from one job to the next. Operators’ engineering staffs can concentrate on other aspects of the drilling and completion process. Since the service company is responsible for procurement of all materials used in the cementing process, quality can be more easily assured. By working more closely with operators or drilling contractors, the service company will have opportunities to make significant contributions in reducing total drilling and completion costs. By utilizing experience gained worldwide in cementing partnerships and by applying the best practices for particular situations, the service company is able to provide improved service to the operator. Allows for possible implementation of incentive agreements for cementing services.

Presented is a discussion of all aspects of the concept, including implementation plans.
A Field Guide for Surface BOP Equipment Inspections
Authors: Kandel W. J. , Streu D. J.
Published: December 2007

This document describes a detailed inspection procedure used to detect faulty BOP stacks and control systems. It includes a comprehensive visual inspection and a hydraulic operator test procedure, both of which enhance a routine pressure test.

The goal of the authors is to provide a field guide to assist wellsite personnel in performing thorough BOP equipment inspections. The ultimate goal is to ensure the BOP stack and control systems are in proper working condition.
Precontract Prescription for Success: A Painless Subsea BOP Inspection
Authors: Rawicki A. T. , Gallander F. B. , Gillis B. T.
Published: December 2007

Performing precontract inspections on subsea blowout preventer stacks and their control systems have proven beneficial to both the contractor and operator. General inspection procedures and actual field results are detailed, and estimated savings are quantified. Contractor perceptions of the program are discussed, as are the benefits of having an inhouse inspection team.
Casing Operations on Deep, Directional, and Horizontal Wells: A New Approach on Planning and Follow-Up
Authors: Possamai Ermenegildo , Bianchi Roberto
Published: December 2007

Centralizer/hole size combinations, minimum centralizer restoring forces and recommended test procedures are specified in API specification 10 D. This specification also includes a recommended procedure for calculating the lateral forces exerted by casing on centralizers in 2-D inclined borehole. However these recommendations are no longer adequate for highly deviated/horizontal boreholes and deep, heavy strings. Extensions are needed in order to consider 3-D borehole curvature variations due to simultaneous changes in hole inclination and direction and to guarantee the influence of external loads on the casing strings.

A computer program, named "Lateral Load Program (LLP)", was developed and field tested during the last few years based on the above assumptions. The LLP has the capability to calculate, starting from wellbore profile data (measured depth, inclination and direction), the dogleg severity, the spacing (constant or variable), the axial and lateral loads. The program also computes the stand-off according to the sag deflection prediction, based on lateral load and tension force from the pipe hanging below the centralizer, and generates a casing stand-off/depth/deviation and the hookload diagrams in advance, representing a valid support for operational planning and follow-up.

Actual field data studies show that the LLP is accurate in predicting the real hookload;in the cased hole such predictions are exact, whereas in open hole they are few tons of the actual up and down weight. As a result of our field experience in many years of drilling activity, it is possible to conclude that achieving a stand-off of 60-70% is not enough to avoid channelling and to obtain proper cement placement. Based on this experience, by late 80's the casing centralizers spacing in deep, deviated and horizontal wells was optimized in order to achieve, as close as possible, a 100% stand-off. Several field examples confirm this assumption. The LLP is still upgrading and the fixed ends boundary condition is used in the last version (’91) for the calculation of casing deflection between two centralizers.
Acid Removable Cement System Helps Lost Circulation in Productive Zones
Authors: Vinson E. F. , Totten P. L. , Middaugh R. L.
Published: December 2007

Lost circulation into a potential producing zone typically creates a dilemma for the drilling engineer: lost circulation materials which are readily removable from the formation typically lack strength, while strong materials like cement can permanently damage the zone. This paper describes laboratory development and field usage of a high-strength cementitious system which is over 96% soluble in hydrochloric acid.

This acid-removable cement has been formulated to have moderately thixotropic properties, but with sufficiently small particle size and low rheologies to penetrate near-wellbore fractures and voids. The synthetic cement is readily mixed using conventional oilfield cementing equipment. Thickening times and fluid loss behavior are controllable up to 220°F fluid temperature using dry-blended additives.

The paper presents laboratory data on slurry properties, strength development, and acid solubility and reaction rates for this cement system. Case histories of field application in instances of lost circulation to a producing horizon are discussed. Potential areas of application in gas storage fields, temporary abandonments of high (or low) pressure zones, and blowout control are also treated.