bluuebunny/crossref_metadata_2025 huggingface dataset:
The Design Considerations of a Multilateral Well
Authors: Lim Ben , Xi Liang Ming , Quan Chen Xi , Chang Zhou Jun , Hua Zhong , Ping Qiu
Published: December 2007

This paper discusses the approach for a reservoir up design of a multilateral well. In the last two to three years, the industry has seen multilateral wells of varying complexities drilled and completed by operators in diverse areas. This paper presents one approach to the design of a multilateral well conducted by a team comprising of operator's and contractor's personnel. The intent of the authors of this paper is to discuss their approach to the selection of a candidate for a multilateral well, the drilling and the completion design of a multilateral well.

The case in point for this paper's discussion is a multilateral well in Beibu Gulf*. The methodology encompasses the full circuit of a well design, beginning with candidate selection, lithology considerations, well engineering, drilling and well profile optimization, fluid considerations, and the final well completion.
Consolidation for Screenless Completions and Proppant-Flowback Control in Hot Wells
Authors: Dewprashad B. T. , Nguyen P. D. , Kuhlman R. D. , Besler M.
Published: December 2007

This paper describes the evaluation and field application of a proppant-consolidation system [as aresin-coated proppant(RCP) is otherwise known] that was developed for treating high-temperature wells (i.e., ≥175°F). Proppant treated with the new high-temperature liquid coating will be called HTL-RCP for the purposes of this paper. The HTL-RCP system is unique in that it is a single-liquid treatment that is used to coat proppants on-the-fly during a treatment on location without the need for specialized metering equipment. The coating promotes adhesion between proppant grains to such an extent that even if the well is flowed back immediately after a treatment, it still cures to give a high-strength consolidation. This paper presents the results of field tests, the evaluation of treatments for proppant-flowback control in tight formations, the application of screenless completions in high-permeability formations, consolidation tests, and breaker-compatibility studies, all of which were conducted under simulated treatment and downhole conditions. The paper describes the development of rock-mechanical testing that was performed to help the prediction of long-term consolidation properties under production conditions of closure stress, cycling, and high bottomhole temperatures (BHTs).

Testing under simulated treatment and downhole conditions indicates that unlike other proppants that are precoated with phenolic resins (P-RCPs), consolidations using the HTL-RCP system do not lose strengths with extended onsets of formation closures. In addition, strengths several times those obtained with other RCPs (using the same amounts of resin) are produced. Rock-mechanical testing indicates that the material is very resistant to cycling and creep. A Mohr-Coulomb failure envelope obtained by rock-mechanical tests indicates that consolidations exceeding strengths required for screenless completions are obtainable under downhole conditions with the material. Treatment with the material does not require additional breaker, resulting in controlled fluid breaks and good cleanup without complicating the fracturing treatment. Effective proppant-flowback control and enhanced productivity were observed in all of the wells treated with the HTL-RCP system.
Evaluating Culture and Language Effects on Safety
Authors: Huang Chunlin , Fu Chengyu , Boben M. E.
Published: December 2007

During the fourth quarter of 1997, a safety perception survey was conducted on three offshore facilities operating by Phillips China Inc.(PCI) in the South China Sea. This survey evaluated the workforce, and their perceived EHS performance with emphasis concentrating on the influence of the different cultures and languages. Opportunities for improvement were identified and then an action plan was developed and implemented.
Nuclear Magnetic Resonance Logging Methods for Fluid Typing
Authors: Hou B. L. , Coates G. R.
Published: December 2007

This is a review paper on applying Magnetic Resonance Imaging Logging (MRIL) methods for detecting and quantitatively measuring volumes occupied by brine, gas, and oil. These methods include Differential Spectrum Method (DSM), Enhanced Diffusion Method (EDM), Shift Spectrum Method (SSM) in transverse relaxation time (T2) domain or in spin-echo time domain (i.e., Time Domain Analysis; TDA), Total Porosity Measurement (TPM), and Injecting Contrast Agent Method (ICAM). The principles, data acquisitions, and data processes of these methods and their applications are introduced and discussed.
Surface-Modification System for Fracture-Conductivity Enhancement
Authors: Nguyen Philip D. , Weaver Jimmie D. , Dewprashad Brahmadeo T.
Published: December 2007

The proppant grain, once coated with a surface modification material, interacts instantaneously with the surrounding particulate because of an increase in surface friction. Experiments show that when such materials are coated with proppants, the settling time of proppants from aqueous-based fracturing fluid is increased. Therefore, the coating results in a better vertical distribution within the fracture and an increase in pack porosity of as much as 30%. API conductivity measurements of proppant packs were found to support this observation, but indicated that closure stress plays an important role in final proppant-pack conductivity. Testing with complete fracturing-fluid systems indicates that improved fluid removal can be achieved under some conditions. Field testing has supported this conclusion by providing both faster and more effective well cleanup after water-based fracturing treatments. Extensive field testing has provided considerable evidence for increased and sustained fracture productivity. Since the surface modification is performed on-the-fly and requires no additional time, aggressive gel-break schedules and well-flowback rates are used. Since most treatments resulted in little or no back-production of proppants or fines, the high-friction surface-modification materials were shown to stabilize proppant packs.
Macroemulsion Rheology and Drop Capture Mechanism During Flow in Porous Media
Authors: Khambharatana F. , Thomas S. , Ali S. M. Farouq
Published: December 2007

Emulsions play more and more important role in the oil recovery as they are found to occur in most enhanced oil recovery processes and are involved in certain modes of crude oil transportation. Furthermore, they can also be used in secondary recovery as blocking agents to improve waterflooding performance in layered reservoirs or under bottom-water conditions. However, there is still a lack of detailed understanding of the mechanisms involved during the displacement process. Therefore, there is a need for understanding the physics controlling the flow of an emulsion in a porous medium.

However, very little research has been carried out in the area of the flow mechanics of emulsions in porous media. Additionally, emulsion rheology and drop capture were investigated separately for certain conditions. These conditions restrict the model to specific applications. This leads to the question of how emulsion transport occurs in a porous medium in the case where emulsion drop size and the pore size are comparable, which is often the case. Therefore, the present study was carried out to observe the physical mechanisms that occurred when a stable emulsion flows in a porous medium for the system of comparable drop and pore sizes. Particularly, emulsion rheologies and droplet captures for both caustic and surfactant emulsions flowing through Berea sandstone and Ottawa sand packs were investigated comprehensively.

The results show that the change in emulsion rheology in a porous medium has an overall trend similar to that in a viscometer for the shear rates of interest. Furthermore, the emulsion droplets were found to be captured according to a filtration process.
A New Multiband Generation of NMR Logging Tools
Authors: Prammer M. G. , Bouton J. , Chandler R. N. , Drack E. D. , Miller M. N.
Published: December 2007

The paper describes the hardware and operation of a new generation of nuclear magnetic resonance (NMR) logging tools. In the past, NMR required the logging engineer to consider the T1 relaxation times of the reservoir fluids likely to be encountered. Actual or simply assumed long T1's translated into slow logging speeds. The new tool generation overcomes this limitation. The key feature is that nine sensitive volumes are polarized in parallel and are read out in rapid sequence. A new sonde design speeds up the polarization process by a factor of 2. Each volume contributes equally to the result, and can support identical measurements for rapid stacking and fast logging, or can be used for individual, simultaneous measurements.

Laboratory data and field test results are presented to demonstrate both the relative simplicity of operation and the improvement in data quality. Logging speeds can be typically upgraded by a factor of 4, while data for total porosity determination and fluid typing are acquired in a single logging pass.
Cyclic Steam Injection on Parallel Horizontal Wells: Geostatistical Description, Thermal Simulation and Field Experience
Authors: Cosentino L. , Spotti G. , Gonzalez J.E. , Araujo Y. , Herrera J.
Published: December 2007

Recent development of Bachaquero 2 Field (Lake Maracaibo, Venezuela) has been based mainly on cyclic steam injection on horizontal wells. Initial oil deliverability of the heated wells proved to be up to 5 times greater with respect to the cold wells.

This paper presents the results of a multi-disciplinary project focussed on the drilling of a pair of horizontal wells for cyclic stearn injection. The project involved a reservoir characterization and a numerical simulation phase, the drilling, steam injection and production of these wells, a data acquisition project and eventually a fial detailed simulation stage.

Experimental and numerical results show that the presence and the thickness of interbedded shale has a severe impact on heat distribution. Very little interference has to be expected between parallel horizontal wells when the separating shale is continuous and its average thickness is greater than about 12 feet. A preliminary stochastic description of the reservoir can be very useful in assessing the presence and expected average thickness of the interbedded shale.

The experience allowed us to set the best production strategy for the 2-horizontal well system, in terms of sequence and duration of the cycles, steam rate, total injected steam, steam quality and soak time. It also helped in setting guidelines for the future development of the Bachaquero 2 Field.

P. 293
Modeling Transient Foam Flow in Porous Media Using a Bubble Population Correlation
Authors: Bertin H.J. , Quintard M.Y. , Castanier L.M.
Published: December 2007

Foam is used in many oil recovery operations (gas mobility control, profile improvement, acidizing etc.). To date, modeling foam flow, specially transient foam flow, is still difficult. Foam viscosity depends strongly on its microstructure (texture), hence, one of the modeling approaches for foam flow in porous media can be done by a population balance equation, giving the bubble density number, that in turn gets included in a classical black oil simulator. Although this type of model produces excellent agreement between theory and laboratory experiments, the degree of difficulty in determining various parameters needed is too high to implement it in commercial simulators,

This study shows a bubble population correlation based on experimental observations and theoretical results obtained at the pore scale (micromodels, network modeling) and at the core scale (transient foam flow in homogeneous and heterogeneous media). In this correlation, we express explicitly the evolution of the mobile bubble density, (the foam texture that governs foam viscosity) as a function of the physical properties of the porous medium (porosity, permeability and capillary pressure) and the evolution of the mobile gas saturation, This correlation has been rather easily implemented in a numerical simulator and the resulting set of data has been matched against results of transient experiments, performed under a CT scanner as well as experiments performed by two other research institutions. The match of the experimental data and the correlation result is excellent. The results have also been compared with a complete simulation using the population balance model. The agreement is excellent between the two types of models.

This simplified formulation allows decoupling the effect of the porous media parameters such as porosity, permeability and capillary pressure from the effects caused by the surfactant, It conserves most of the benefits of the physics of foam flow as seen in the literature and allows simulation of heterogeneous porous media.

P. 319
Sub-seismic Faults Can Seriously Affect Fluid Flow in the Njord Field off Western Norway - A Stochastic Fault Modeling Case Study
Authors: Damsleth Eivind , Sangolt Vegard , Aamodt Geir
Published: December 2007

The Njord Field is heavily faulted. A stochastic fault modeling study has been performed on a sector of the field to quantify the potential impact of sub-seismic faulting on the production. Emphasis was given to the sensitivity of the results to the number of sub-seismic faults, the fault orientation, and the fault sealing properties. The main conclusions are: - Sub-seismic faults have neglectable effect on recovery, nor on the shape of the production profile, unless they are almost completely sealing. - The distribution of strike directions had no effects on the production.–Recovery decreases with increasing number of sub-seismic faults.–A large number of sealing sub-seismic faults will on average reduce the sector production with 20–25 %, compared to a base case model without sub-seismic faults. In some cases the reduction is much worse.–The production from individual wells is much more sensitive than the sector total to sub-seismic faults. Reductions up to 80 % have been observed in the simulations.

The HAVANA software has been used for the sub-seismic faults modeling. Irap RMS has been used for visualization and quality control, and the effects of the sub-seismic faults on production have been investigated using the fluid flow simulator Eclipse. HAVANA has proved to be very useful for this kind of studies.

P. 295
Probabilistic Reserves Lead to More Accurate Assessments
Authors: Schuyler J.R.
Published: December 2007

Property evaluations are key inputs for decision-making. Reserve category definitions-guidelines to petroleum property evaluation practice-intentionally produce conservative reserve valuations. Additional biases, actually errors, are introduced inadvertently. Many evaluation engineers are unaware of fundamental statistical processes that apply.

This paper describes two issues arising with the application of probabilistic techniques in reserve estimations. The first is aggregation of properties. This topic is identified, though without guidance, in the new SPE/WPT reserve definitions. Can we obtain proved reserves from a portfolio of probable reserves? Does a property's acquisition affect its reserves? Can we get proved reserves by aggregating probable or possible reserves? Professionals asked about these issues have admitted mixed levels of understanding and had diverse opinions as to best practice.

A second, companion issue is that monetary values are more important for deeision-making than reserve volumes. Therefore, prices and other economic assumptions are critical. In probabilistic reserve assessments, probability distributions express judgments about uncertainties. Forecast calculated with probabilities lead to more complete and more accurate evaluations.

P. 179
Temperature Prediction for Deepwater Wells: A Field Validated Methodology
Authors: Romero J. , Touboul E.
Published: December 2007

A precise knowledge of downhole circulating temperature is necessary for the design of safe well construction operations. The reliability of existing correlation and models is sometimes reduced in deepwater wells. Indeed, the mechanism of heat exchange with the sea is more complex than for rock formation, requiring additional inputs such as sea current, riser geometry and insulation. This paper describes an advanced numerical simulator for the design and evaluation of downhole circulating temperatures during drilling and cementing operations in deepwater wells. The equations governing heat transfer between the wellbore and the sea are developed first.

Several methods for obtaining offshore temperature measurement are presented and recommendations are given to use measurement while drilling (MWD) data as part of the design and evaluation process for wellbore temperature. A field case is then presented to illustrate how such MWD data can provide meaningful information for determining circulating and static temperature on deepwater wells. The down-hole measurements were compared to simulated temperature to illustrate how the MWD temperature can be correlated to bottom-hole circulating temperature. Finally, a methodology is proposed to assess the effect of deep water on circulating temperature and cement design based on MWD temperature measurements.

P. 339
Pipeline's Progress - A North Slope Update
Authors: Henriksen Donald A.
Published: December 2007

The Prudhoe Bay oil field, discovered in 1968 on the North Slope of Alaska, is the largest oil field in North America. The Trans Alaska Pipeline System, designed to transport Prudhoe Bay crude oil to an ice-free port on Prudhoe Bay crude oil to an ice-free port on the south coast of Alaska, will be the largest and most expensive construction project financed and built by private enterprise. Prudhoe Bay and TAPS jointly will have a Prudhoe Bay and TAPS jointly will have a major impact on future West Coast energy supply.

The history of North Slope petroleum exploration leading to the Prudhoe Bay discovery is briefly reviewed. Plans for the development of the Prudhoe Bay field are outlined, together with a general description of the producing facilities. The history of the Trans Alaska Pipeline System is reviewed, and current construction plans are described.
New, Low-Viscosity Acid-In-Oil Emulsions Provide High Degree Of Retardation At High Temperature
Authors: Crowe C.W. , Miller B.D.
Published: December 2007

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

This paper was prepared for the Rocky Mountain Regional Meeting of the Society of Petroleum Engineers of AIME, to be held in Billings, Montana, May 15–17, 1974. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is granted upon request to the Editor of the PETROLEUM ENGINEERS JOURNAL is granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made.

Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the SPE magazines.

A highly retarded acid emulsion has proven extremely effective in the stimulation of hot limestone and dolomite formations. The level of reaction rate retardation achieved with this acid is much greater than previously possible and is obtained through use of a unique surfactant system which both emulsifies the acid and forms a chemical barrier on the surface of the rock. Acid reaction rate studies performed in the laboratory under both static and flowing conditions demonstrate its high level of retardation.

In contrast to previous emulsified acids, which depend upon high viscosity for retardation, this emulsion has a viscosity of only 30 cps, thus greatly reducing pumping pressure and allowing increased injection rate. Due to its slow reaction rate and improved pumpability, acid penetration distance is greatly increased. Comparative well results clearly demonstrate the increased effectiveness of this type retarded acid.

Introduction

Most acid treatments can generally be classified as either fracture or matrix acidizing. Matrix treatments are performed at pressures below that required to produce hydraulic fracturing and have as their main purpose the removal of formation damage in the area immediately around the wellbore. Acid fracturing treatments are performed at pressures above fracturing pressures, usually at greatly increased injection rates. pressures, usually at greatly increased injection rates. These treatments are designed primarily to improve the natural flow characteristics of the well by the creation of artificial flow channels deep into the formation. In contrast to ordinary hydraulic fracturing where fracture conductivity is produced by the placement of sand or other propping agents acid fracturing achieves conductivity by propping agents acid fracturing achieves conductivity by the non-uniform etching of the fracture faces.
Capital Formation In The Energy Industry
Authors: Marx James F.
Published: December 2007

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

This paper was prepared for the 1974 Eastern Regional Meeting of the Society of Petroleum Engineers of AIME, to be held in Washington, D.C., Nov. 14–15, 1974. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made.

Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the SPE magazines.

A simple, but unrealistic conclusion to draw from the existing energy shortage is that never before have so many done so much to achieve so little. With the help of the media and doomsday forecasters the good news has been overshadowed by the bad. Through the ages man has invariably, with varying degrees of success, managed to apply fresh ideas and technology to achieve his needs.

Recently we experienced results of Government intervention in the realm of supply and demand - the action taken being wage and price controls. Historically, shortages are best relieved when prices are allowed to exercise their influence on consumer habits and thus create a motivation for producers. How else can a real expression of values emerge in a realistic fashion? Perhaps some of you witnessed a recent film clip on an 11 o'clock TV news broadcast depicting Wisconsin cattlemen slaughtering calves in protest against recent feed costs coupled with an inability to achieve offsetting higher cattle prices. Taken into our own perspective, in 1954 the FPC was empowered to set artificial well head prices on interstate sales of natural gas-stimulating consumer demands, but discouraging producer incentive to promulgate continued supply in sufficient quantity. Hopefully none of us here today subscribe to the theory that government intervention in the marketplace is the panacea for a faltering system caused by an inability panacea for a faltering system caused by an inability to provide an adequate supply of a commodity at a fair price. price.
Formation Fracturing with Foam
Authors: Blauer R.E. , Kohlhaas C.A.
Published: December 2007

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

Over sixty wells have been treated with hydraulic fracturing techniques with foam as the fracturing fluid. These foams contained as much as 95% gaseous phase; most treatments used foams with gas contents in the 65% to 85% range. Foam has several desirable properties for use as a fracturing properties for use as a fracturing fluid: high sand-carrying and sand-suspending capability, low fluid loss, low hydrostatic head, low pressure drops due to friction, quick fluid recovery, low formation damage, and no reduction of fracture conductivity due to fluid ingredients. Most applications of foam as a fracture fluid have been in low permeability gas reservoirs. Several permeability gas reservoirs. Several oil reservoirs have also been successfully treated, however. Cost of the treatment is approximately the same or slightly less than a treatment with conventional fluids of comparable volume and rate.

Introduction

Foams used as fracturing fluids are dispersions of gas, generally nitrogen, in a liquid, generally water, with a small amount of surfactant foaming agent added. Volumetric gas content (referred to as foam quality) is generally between 65% and 85%. Qualities as high as 95% have been used. Surfactant content is commonly 0.5% to 1% of liquid volume. Stability is increased by addition of more surfactant, whether foaming agent or gelling agent. Such foams are homogeneous mixtures with a narrow range of bubble size, mean bubble size less than 200 microns, and are stable for periods of several hours.

During a fracture-treatment operation, the liquid phase passes through a blender and is mixed with sand and then passes through the injection pump which raises the pressure to required injection pressure. Surfactant foaming agent is added downstream of the injection pump and gas is introduced with a tee or lateral downstream from the surfactant. Foam is generated at the point of gas introduction (see Figure 1). The gas is transported to the site and stored in cryogenic tanks and added to the injection stream at line pressure.

The foams used for fracturing are similar to those described previously by several investigators.
Increasing Availability - The Benefits of Introducing an Integrated Corrosion Management System
Authors: Nielsen Mette Fraas , Bingham Simon
Published: December 2007

Oil and gas operators are continuously encouraged to reduce operating costs per Barrel of Oil Equivalent (BOE) by minimising operations costs and optimising operability. A proactive approach to corrosion management is, for one operator, proving to be successful, whilst maintaining a safe operation ensuring no accidents, harm to personnel, or damage to the environment.

Apache Energy Limited (AEL) have developed a Corrosion Management System (CMS) using factors and resources already available and supplemented them where appropriate, with additional elements:

– A Risk and Consequence based approach to Corrosion Risk Assessment (CRA) and Inspection Scheduling was used. – Initial effort identified existing elements that could remain in place and supplemental elements required to form a cohesive, focused and commonly applicable system. – The supplementary elements of the CMS were implemented on an ongoing basis, dealing with the priority parts first, building around existing elements. – Core staff and competent personnel operate the CMS with minimal input. Ownership of the system by on-site operators and others in the field is a key factor to its success. – The CMS specifies anomaly criteria and target values for all data sets collected via manual and automated instrumentation for feedback, trending and comparison.

The feedback loop is essential for the continuous improvement of the system. Audit of technical practices and adherence to the documented requirements is undertaken periodically and independently.

The AEL CMS currently covers the East Spar and Harriet Gas Gathering Projects though has been implemented such that extension to cover other facilities is relatively straightforward. A CMS can be implemented any time during the life of the plant, facility or asset. Early implementation of the system will maximise the benefits of the system. Towards the end of the life of a plant the cost benefits may be limited.

P. 241
A Multiple Realisation Approach to Managing Uncertainty In The North Rankin Gas Condensate Field, Western Australia
Authors: Twartz S.K. , Gorjy F. , Milne I.G.
Published: December 2007

A multiple realisation approach was used in the management of ultimate recovery uncertainty of the North Rankin gas condensate field. The aim of this approach was to identify the key uncertainties that impact ultimate recovery, reflect those uncertainties in discrete realisations as represented on a realisation tree, use the discrete realisations to improve the quality of development decisions, and to evaluate the uncertainty on field ultimate recovery. Emphasis was placed on the use of production data, primarily pressure and TDT data, to reduce the range of possible realisations, assign probabilities to realisations and hence reduce the ultimate recovery uncertainty.

This paper provides a clear and practical process for management of uncertainties from the probabilistic and deterministic perspective. The process is comprehensive and covers all steps leading to final reporting of field ultimate recovery. The steps in the process are clearly demonstrated by actual examples from the North Rankin study.

P. 261
Transversely Fractured Horizontal Wells: A Technical Appraisal of Gas Production in Australia
Authors: Crosby D.G. , Yang Z. , Rahman S.S.
Published: December 2007

A large, though relatively untapped tight gas resource is thought to exist within Australia. Experience from the North Sea and the United States suggests that transversely fractured horizontal wells may be used to exploit tight gas resources more effectively than more conventional means, such as fractured vertical wells or fully completed horizontal wells. However, transversely fractured horizontal wells are relatively expensive completion options, and are commonly afflicted by complications associated with complex fracture geometries. Therefore, careful planning and screening of prospective reservoirs is essential. Using an analytical pseudo steady state inflow model, this study reviews the reservoir conditions required for the successful application of transversely fractured horizontal wells. To avoid fracture reorientation, transverse fractures should ideally be initiated directly from the wellbore and possess no longitudinal components. Reservoirs which possess natural fractures or create large differential stresses across horizontal wellbore sections will be predisposed towards the successful placement of transverse fractures. Guidelines are presented which enable the identification of such reservoirs. A case study has been performed which demonstrates the applicability of transversely fractured horizontal wells in the context of Australian tight gas reservoirs.

P. 315
Competence Skills Portfolio for Technical Staff - A Career Development Focus
Authors: Adams D.R.
Published: December 2007

This paper outlines Woodside's Competence Development Process. It explains how competence relates directly to performance improvement and how it relates to other processes such as Position Descriptions, Recruitment, Promotions, Performance and Development reviews and Talent Spotting, etc.

During 1996 it was decided to enhance the focus on both Performance and Competence at an organisational, departmental and individual level. The reason for the increased attention was to: - Elevate performance.

– More closely align organisational, departmental and individual targets so that people spend their time doing activities which improved performance. – Equip individuals with the specific skills, knowledge and abilities they need to be able to meet their own and their group's targets. – Provide a mechanism for the selection of individuals for positions to be made on the basis of competence.

Woodside like most companies, have a number of Human Resources systems designed to improve the capability of our employees by improving their competence. However these are only INPUTS and unless they are focused on achieving the desired OUTPUTS they will not necessarily result in improved performance, even if they improve the individual employee's personal development. This can be depicted as follows:

To ensure competence was used to improve performance it was necessary to develop an improved process for identifying competence and applying it to workplace requirements.

P. 375
Outsourcing of Minor Material Purchasing
Authors: Foley Peter W.
Published: December 2007

Within all organisations and particularly in the oil and gas industry there is a need to procure items of minor dollar value. These items may be small specialised items or straight consumables and normally add very little to the core business of an organisation if the items are not readily available. The process of minor material procurement typically does not add value to an oil and gas operator in terms of efficiency and economics. This paper outlines the recognition that minor material procurement is typically a non value adding activity. A number of topics are presented to illustrate the approach and the benefits of outsourcing minor materials procurement. Purchasing statistics are reviewed followed by the introduction of a strategic approach to guiding procurement to a value adding activity. The methodology used in the outsourcing and the concepts that have been implemented are discussed.

P. 393
Trends For Future Gas Supply Planning For Gas Utilization Projects In Malaysia
Authors: Abdullah Mohamad
Published: December 2007

The Malaysian gas era started in 1983 with the commencement of the LNG project in Bintulu, Sarawak. This was followed by the Peninsular Gas Utilization Project (PG U) and the Sabah Gas Project in 1984. The gas resources in Sarawak are developed mainly for supply to the LNG project, for export to Japan, Korea and Taiwan with a small portion consumed domestically for power generation and as feedstock to fertilizer plants.

The gas resources in Peninsular Malaysia are developed mainly for domestic utilization with some 150 million SCF/D exported to Singapore. The gas from the PGU project in Peninsular Malaysia is consumed for power generation, industrial and residential usage. In addition, the gas is also used as feedstock to a more value added petrochemical industry.

Gas has now become a major contributor to the national economy besides oil. It has a dual role as a source of energy and a major exchange earner for Malaysia. To ensure that gas continues to play this important role, a long tern, sustainable gas supply is vital for Malaysia. To meet the future growth in gas demand both for export and domestic consumption, gas production in Malaysia is projected to increase from the current level of 5,300 million SCF/D to about 6,600 million SCF/D by year 2002.

The paper will discuss an evaluation of future challenges relating to gas supply planning in order to meet the projected long term gas demand in Malaysia. Trends in expected future discoveries, development concept, development technology and project economics will also be discussed.

P. 489
Predicting the Stability of Horizontal Wells and Multi-Laterals — The Role of In Situ Stress and Rock Properties
Authors: Moos D. , Peska P. , Zoback M. D.
Published: December 2007

Drilling problems frequently result from severe mechanical failure of the wellbore wall and thus depend on the interplay between the magnitude and orientation of in situ stresses, rock strength, mud weight, and the orientation of the wellbore. Utilizing a new suite of software tools developed to study wellbore stability in a wide variety of geologic environments, we can accurately predict optimally-stable wellbore trajectories from knowledge of the stress tensor. The analysis is a two step process – first, we determine stress from observations of failure in existing wells. We can then apply this knowledge to predict the stability of proposed wells both while drilling and later during production. We illustrate this type of approach using three case studies. First, we combine observations of failure in a vertical well with rock strength measurements to demonstrate the feasibility of horizontal drilling in poorly consolidated reservoir sands. Next, we analyze the stability during production of a series of multilaterals drilled from a single inclined parent well. Finally, we show that wellbore stability can be controlled by the orientation of a well with respect to bedding, and illustrate a method to optimize the trajectory of wells to account for this effect.
Successful Flank Appraisal with a Horizontal Well: A Niger Delta Example
Authors: Ohanele Chris , Emelumadu Ubaka
Published: December 2007

This paper was prepared for presentation at the 1998 SPE International Conference on Horizontal Well Technology held in Calgary, Alberta, Canada, 1-4 November 1998.
Optimum Fluid Design for Drilling and Cementing a Well Drilled with Coil Tubing Technology
Authors: Svendsen Ø. , Saasen A. , Vassøy B. , Skogen E. , Mackin F. , Normann S. H.
Published: December 2007

This paper describes the strategy, design and the drilling fluid and cement operations in the first two wells drilled with Coil Tubing on the Gullfaks field. The strategy and design is explained in great detail. Excellent hole cleaning was achieved in both wells.

A serious problem of differential sticking was eliminated by a radical change in drilling fluid strategy and design. It was possible to successfully drill a 3 ¾" hole, log and run/cement a 2 7/8" liner at a maximum inclination of 122°.

A virtually solids free Potassium Formate Brine/Polymer drilling fluid with a density from 1.50 – 1.56 g/cc was used. The flow properties of the drilling fluid is characterised by a very low fluid loss due to a high extensional viscosity, a low viscosity at all shear rates and a low degree of shear-thinning.
Heavy Crude Production from Shallow Formations: Long Horizontal Wells Versus Horizontal Fractures
Authors: Valkó Peter P. , Economides Michael J.
Published: December 2007

This paper studies the feasibility of producing heavy oil from shallow formations using either long horizontal wells or short horizontal wells fractured horizontally. The suggested withdrawal configuration provides excellent well / fracture communication and additional sand control. The problem of optimum proppant placement is solved in two steps. First, finite conductivity fracture performance is considered in general terms. It is shown that the performance can be described as a function of two dimensionless parameters. Optimum conditions are derived. Then the solution is applied to the horizontal fracture configuration. The performance is compared to that of a "long" horizontal well.
Sleeving-back of Horizontal Wells to Control Downstream Oil Saturation and Improve Oil Recovery
Authors: Greaves M. , Saghr A. M.
Published: December 2007

Air injection is developing as a broad based IOR technology, applicable over a wide range of reservoir conditions, including heavy, medium and light oils. In remote and offshore locations, air represents a cheap source of injection gas for implementing a number of different recovery processes. In light oil reservoirs, there are three possibilities: if the oil-rock matrix reactivity is low, then the oxidation reactions will be limited to low temperature oxidation (LTO) and either the net thermal effect in the reservoir will be close to zero, i.e. isothermal at a low gas rate, or a thermal displacement will develop at significantly higher temperatures (still LTO), but only at a much higher gas injection rate. If, on the other hand, the oil-rock reactivity is high, high temperature oxidation (HTO) reactions will take place which, with a sufficiently high air injection rate, an in-situ combustion front can be propagated through the reservoir. A necessary requirement for all air injection processes is that the oxygen be completely removed via oxidation reactions, or at least to a sufficiently low level.

One problem observed in light oil reservoirs is the tendency to de-saturate the oil layer downstream of the moving front, particularly with thermal IOR processes, because of the additional vaporisation which occurs and high oil mobility. Low pressure ISC tests were carried out in a 3-D cell equipped with an extensive thermocouple array. In order to restrict the de-saturation of the oil layer, a modified horizontal producer well, incorporating a ‘sleeve-back’ principal was used. The idea was to mimic the ‘Toe-to-Heel’ displacement process occurring during heavy oil recovery, wherein the downstream oil is essentially immobile due to its high viscosity. The ‘sleeve-back’ of the well was achieved using a co-aligned, two well assembly, so that the upstream section of the horizontal producer well is active, and continually adjusted during propagation of the combustion front.

Significant improvement in overall stability of the process was observed using the ‘sleeve-back’ modification, as attested by sustained propagation of the combustion front, high levels of produced CO2 and high oil recovery.
Enhanced Calibration Treatment Analysis for Optimizing Fracture Performance: Validation and Field Examples
Authors: Gulrajani S.N. , Vasudevan S. , Ganguly U.
Published: December 2007

Current pressure evaluation techniques that assess fracture behavior from calibration treatments are limited to predicting reservoir parameters that govern fracture growth. In addition, significant variability during the evaluation process can result in subjectivity and hence reduce the effectiveness of such tests. The recently proposed "after-closure" analysis attempts to overcome these limitations by assessing the reservoir- dominated pressure response, following mechanical closure of a hydraulic fracture. After closure linear flow provides an independent assessment of the fracture length induced during the calibration treatment. This prediction constrains the fracture length predicted, either by the conventional pressure decline analysis or a numerical fracture simulator, and hence provides an accuracy check for the pressure evaluation. In addition, the dependency of the pressure response during the linear flow regime on the closure time permits an additional independent assessment for fracture closure pressure. Consequently, the linear flow diagnostic reduces uncertainty in determining the fracture closure pressure that is commonly encountered during the evaluation process. Finally, the reservoir pressure and transmissibility are estimated from the radial flow behavior in a manner similar to conventional well testing. The proposed evaluation methodology combines this after-closure analysis with conventional calibration treatment analysis to predict a cross-validated ensemble of all parameters that govern proppant placement and post stimulation hydrocarbon production. This evaluation methodology thus provides all information required for an optimized design of fracture treatments.

The methodology of this analysis, as well as comprehensive field examples illustrating its application and validity, are presented in this paper.

P. 375
Development and Trends in Hydraulic Fracture Stimulation of German Rotliegend Gas Wells
Authors: Berghofer K.
Published: December 2007

Over the past 15 years there have been significant changes in the design and operational aspects of fracture treatments of German Rotliegend gas wells.

The paper presents a review of pump volumes, pump strategies and post-frac production behavior, from the hydraulic fracture treatments of tight Dethlingen sandstone formations in the Sohlingen field in the eighties to the stimulation of high capacity wells in 1997.

The consistent use of bottom hole pressure gauges with surface readout in mini fracs, and the application of real time 3D fracture stimulation software resulted in the continual reduction of pump volumes in main fracs and the related time and cost requirements.

In frac treatments of Rotliegend gas wells there is a clear trend toward smaller proppant volumes, while the post-frac production rates are going up. The production rates of frac-treated wells were max. 10,000 Sm3 in the early eighties, but have meanwhile gone up to 45,000 Sm3.

Post-fracture analysis showed that, with decreasing reservoir pressure, the risk of uncontrolled fracture growth and proppant convection due to underhydrostatic closure pressures increases. Therefore, it appears desirable to stimulate Rotliegend gas wells before reservoir pressure declines to below the critical level.

The future development of fracture stimulation technology is seen to bring an ongoing decrease of proppant volumes pumped in one stage, and the application of multistage fracturing using coiled tubing to place proppant.

P. 569
Application of Novel Upscaling Approaches to the Magnus and Andrew Reservoirs
Authors: King M.J. , MacDonald D.G. , Todd S.P. , Leung H.
Published: December 2007

Cases studies from three North Sea turbidite reservoirs will be presented, which together demonstrate our current understanding of permeability and relative permeability upscaling. The three formations, the Magnus, Magnus Sand Member (MSM), the Magnus, Lower Kimmeridge Clay Formation (LKCF), and the Andrew reservoir each provide distinct challenges for reservoir modelling, either because of reservoir complexity, the fluids in place, or the phase of field life. To meet these challenges, several novel upscaling approaches have been developed. Their use will be explored and current best practice delineated. This best practice differs significantly from previous definitions of "effective permeability" by placing more emphasis on extracting multiple properties from the fine scale geologic models. Distinct upscaling calculations are required to assess

the quality of sands, the quality of barriers, and the tortuosity of flow around these barriers.

Similarly, when constructing upscaled relative permeabilities, the "effective" curves are distinguished from the "pseudo" curves. The former describe the physical displacement of fluids, while the latter include the additional numerical dispersion corrections required when implementing the relative permeability functions within a coarsely gridded full field simulator.

P. 133
Novel Lubricants for Water-Based Drilling Fluids
Authors: Growcock F. B. , Frederick T. P. , Reece A. R. , Green G. W. , Ruffin M. D.
Published: December 2007

As drilling in directional and extended-reach wells continues to gain popularity, high torque and drag become increasingly important issues. This is particularly true for water-based muds (WBM), which generally give rise to high coefficients of friction (COF) between the drillstring and the wellbore and, therefore, high torque and drag. In addition, water-based muds can also increase wear rates in the wellbore. For contact between steel and rock, oil-based muds (OBM) and synthetic-based muds (SBM) generally produce COF that are lower than those produced by WBM. However, use of OBM and SBM is severely limited by environmental concerns and high costs. It would be advantageous to identify environmentally friendly WBM that are as lubricious as OBM and SBM.

This paper discusses a recent project the aim of which was to find suitable lubricants for WBM that would reduce the COF between drillstring steel and sandstone without having adverse effects on the formation or the environment. Laboratory COF measurements are shown to correlate with simulated field results. Trends in lubricant performance appear to be relatively independent of the type of mud system, although absolute performance decreases with increasing solids content and the presence of other surface-active components. A simple mechanistic lubricity model is described that emphasizes the role played by lubricant-induced wettability changes.