bluuebunny/crossref_metadata_2025 huggingface dataset:
Groundwater Monitoring: A Proven Sampling System for Environmentally Sensitive Areas
Authors: Welch W. R. , Dines C. A. , Shy Perry
Published: December 2007

In a groundwater reservoir, pollutants generated by various industrial processes can be present, and in many cases, can be radioactive or hazardous for other reasons. Operational trends in the oilfield have continuously stressed operational efficiency, and with it, safety of personnel and the environment. Now, however, a pronounced increase in regulatory requirements has been noted, which attests to the fact that there is increased governmental awareness throughout the world of the existence of these potential dangers. Subsequently, the need to monitor groundwater sources to ensure that contamination resulting from pollutants does not exceed levels of safety has reached new levels of importance in industrial operations.

A system that can respond to this need has recently been developed from proven oilfield technology. This system has the capability to monitor groundwater sources by sampling groundwater from potentially contaminated aquifers without damaging the wellbore or the well formation and efficiently segregating the sample into a safe, clean, and controlled environment.

The system incorporates a subsurface-actuated isolation device, which is permanently installed as part of a borehole/well completion. Suspect groundwater sources can be sampled by running a multi-function electro-mechanical tool on electric line into this isolation device. Once the locking profile in the isolation device has been located, a sequence of events is initiated from the surface that ultimately results in a sample being captured within the isolation device.

Since many contaminants are hazardous, the sampling system operates in a manner such that the wellbore is protected from exposure to any of the sampled fluids, and at the same time, the formation is protected from exposure to wellbore fluids. After the sample(s) is captured, it is brought to the surface and transported in an intrinsically-safe, pressurized container to a laboratory for analysis.
Application of the Incident Potential Matrix Technique to Marine Seismic Operations
Authors: Karlsson T. V. , Jahre B. M.
Published: December 2007

This paper describes a marine seismic operation in Europe and Africa which operated on average 15 deep marine seismic vessels in 1993. Most of the vessels were active in the North Sea. The majority of the vessels were involved in complex multistreamer 3D seismic projects.

An integrated plan has been developed to minimise the risk of accidents happening in this operation. An electronic mail system is used to report accidents and near-accidents to the office.

Investigations are initiated onboard the vessels and in the office to identify root causes and necessary actions. Actions may involve improvement of equipment, development or improvement of procedures or new training programs for personnel.
Environmental Monitoring as the Basis for Effective Management
Authors: Wright R. A. D.
Published: December 2007

There is an assertion that "what you can't measure you can't manage". This is especially true for environmental management which has the particular difficulty of addressing a variety of issues with generally qualitative and moving targets associated with them. Effective environmental management requires that the issues are clearly defined, that goals and objectives are specified, and that where possible these are translated into quantitative targets against which performance may be monitored.

Australia's North West Shelf Gas Project involves the production of gas at North Rankin ‘A’ platform some 130km offshore and its transport by pipeline to an onshore treatment and liquefaction plant (see Figure No.1). The liquefied natural gas (LNG) is shipped to Japan. Environmental protection has been an essential feature of the Project since its inception twenty years ago. The environmental management system that has emerged can best be described by reference to Figure No. 2. The key issues are defined in a strategic plan. Goals and objectives for these issues are specified based on legal compliance, industry norms, and company policy which is to better these standards wherever practical. The main environmental issues for the North West Shelf Gas Project have been, identified as: drilling mud and cuttings discharges, planning new developments. product i on eff1uents, production emissions, ozone depleting substances, liquid and solid wastes and contingency planning.

Monitoring performance related to these issues is done in four ways: Routine discharges (effluents, emissions and waste) are regularly quantified.Non-routine discharges such as spillages are reported as soon as they occur.Effects are assessed through a programme of studies of key features of the environment.The adequacy of the environmental management system is checked by a dedicated audit every three years.
Base Line Study of the Tambora-Tunu (TATUN) Gas Field
Authors: Dwistiadi Dyan , Alamsyah Chandra , Soeprijadi Soeprijadi
Published: December 2007

Situated in the Mahakam Delta on the East Coast of Kalimantan, Indonesia, mainly in the inter-distributory zone, development of TATUN gas field may have some environmental impacts such as destruction of the vegetation by dredging, possibility of pollution and erosions caused by the drilling (especially which use oil base muds) as well as impact due to local population activities.
Coiled-Tubing Drilling: A Directional Service Company Point of View
Authors: Lenhart R. A.
Published: December 2007

Horizontal and highly deviated well bore drilling has been the catalyst for developing new and innovative drilling techniques and procedures over the last 10 years. Coiled tubing drilling is one of these new techniques which has proven its viability after being employed to drill five slimhole horizontal well bores. This paper will discuss drilling tools, drilling procedures, and surface equipment as it compares to conventional slimhole steerable drilling equipment and techniques.
Balanced Drilling with Coiled Tubing
Authors: MacDonald R. R. , Crombie D. L.
Published: December 2007

Re-entry and under balanced drilling have accelerated interest in coiled tubing drilling. Whether this interest is attributable to a prize of lower cost wells or improved productivity due to reduced formation damage, the technique has the potential to have significant impact on reservoir depletion plans. This paper presents the strategy used to drill at or near balanced reservoir pressure with coiled tubing and foam. Surface handling of wellbore effluent, particularly when sour reservoirs are being drilled, necessitates that the surface system effectively break the foam to allow safe handling of the effluent. Full scale testing of separation equipment provided the necessary data to design the surface system. Down hole, real time monitoring of bottom hole pressures both inside the coil and in the annulus was accomplished. This allowed calibration of a circulation model and real time control of the bottom hole pressure.
The Fatigue Life of Coiled Tubing
Authors: Sisak W. J. , Crawford D. J.
Published: December 2007

A model of coiled tubing fatigue is presented. Failures at high internal pressure are predicted when the net cumulative axial plastic strain reaches a critical failure strain that can be approximated as the local fracture strain measured in a uniaxial tensile test. Failures at low internal pressure can be predicted using standard low-cycle fatigue approaches. Fatigue-life predictions using the new model are in close agreement with results of full-scale tests of 70 ksi yield, 1-¼-inch OD, 0.087-inch wall thickness steel coiled tubing manufactured by the conventional resistance weld and anneal process. Plots are developed that relate fatigue life to hoop stress and axial strain amplitude. Based on these curves a methodology is proposed that can be used together with full scale data as a guide for selecting drilling conditions to optimize tubing fatigue life.
Minimum Area Rig Concept: Second Generation
Authors: Fullerton R. D. , Svendson L. F.
Published: December 2007

The Minimum Area Rig Concept (MARC) platform rig continues to be a cost effective alternative to the typical self contained platform rig. The first MARC platform rig, Helmerich & Payne International Drilling Company's Rig 101, was designed for ARCO Oil & Gas Company. It has been working in ARCO's South Pass 61 field of the Gulf of Mexico since 1983. A paper introducing the original MARC rig was presented by ARCO to the 1983 IADC/SPE conference1. ARCO's success with H&P Rig 101 has led to the development of a second MARC rig. Current technology and operating experience assisted H&P in engineering, building and operating a second generation MARC rig, H&P Rig 108.

The purpose of this paper is to present an overview of the selection, design, construction and operational characteristics of the H&P Rig 108 MARC rig. Improved rig design and advances in equipment technology led to a rig that combines the operational efficiencies that benefit the operator and mechanical efficiencies that benefit the contractor. The MARC rig maintains its original design parameter of moving without a derrick barge in addition to providing H&P with a more versatile platform drilling fleet. Other upgrades that are addressed include a TDS-3H top drive system, larger capacity cranes cascading shaker system, larger engines and pumps, a BOP handling system and a vertically erecting mast.

In summary, a decade of operational experience with the original MARC rig design coupled with advances in industry technology has led to the construction and operation of a second generation MARC rig.
Performance of a Complete ABS Special Survey with Repair of an EPU While on Location
Authors: Hinloopen Gerry
Published: December 2007

The "Ocean Zephyr", a semisubmersible drilling unit, was converted to an FPU in stages, the latest upgrade being performed in the latter part of 1987 after which it was connected via flexible flow lines to subsea well completions and sales lines in Petrobras' Viola Field offshore Macae' Brazil. This made the unit a significant component of the entire fields production, a fact which five (5) years later made it very undesirable to remove it from service even for a short period.

In early 1993 the rig was due for ABS surveys including renewal inspections for Load Line and Class, Drydocking, MODU, etc. In addition, repair work was scheduled to renew large areas of column shell plate at the wind and wave elevation which was discovered wasted during normal company inspection and maintenance. Both parties, the operator and contractor had strong economic incentive to find ways to perform this work offshore without disruption of production, rather than shut in production and bring the unit into sheltered waters, generally at an established shipyard. To complicate the operational planning a corporate decision was made to ensure that the operator was not inconvenienced during this period.

This paper explores the preparations and modifications performed prior to the unit's conversion to - an FPU so this type of inspection and repair can be done on locations as well as the pre-project planning. It also addresses the special considerations for major hull shell plate renewal at and below the water line without shutting in or loss of production. The "Ocean Zephyr" yields insight into resolving the problem facing FPU's for long term operation at a single location while meeting regulatory body requirements and performing repairs to the areas most susceptible to damage and wastage.
Integrated Automation for a Mud System
Authors: Murch D. K. , White D. B. , Prouvost L. P. , Michel G. L. , Ford D. H.
Published: December 2007

In today's operating environment we strive to increase safety, improve working conditions and reduce costs. Optimum control of the mud system, which is at the heart of drilling, is a key contributor to successful operations and to meeting these objectives.

This paper describes a joint industry project to demonstrate the potential benefits of an integrated, automated mud system. This system has combined recent developments to produce an overall package which offers characteristics of safety, environmental acceptability, efficiency, economics, operability and ergonomics. Some of its key sub-components are:

– Automated monitoring of solids control equipment – Automated addition of mud chemicals – Continuous monitoring of key mud parameters – Automation of mud system valve control and tank line up – Central monitoring and integrated process control

A demonstration system has been installed on a working offshore rig for full scale evaluation during late 1993 and the first half of 1994.

An extensive study was made of the manpower and activities needed for mud system operations on rigs worldwide. This work helped to define the system and will form a bench mark against which the benefits of the new system, in terms of HSE, cost reduction and quality, can be evaluated.

In this paper we describe mud activities on today's rigs, the development of the demonstration system, its implementation and the methods currently being used to prove its benefits.
Glycol-Enhanced Water-Based Muds: Case History to Demonstrate Improved Drilling Efficiency in Tectonically Stressed Shales
Authors: Twynam A. J. , Caldwell P. A. , Meads Kevin
Published: December 2007

Glycol and glycol derivatives are now being used to enhance water based muds and the use of such systems can have a real application in areas where oil based muds would be considered as first choice. Results (both from the laboratory and field use) indicate that glycol type and concentration can be modified to suit a particular drilling application: to effectively reduce HTHP fluid loss values, improve shale inhibition, increase lubricity and reduce differential sticking potential.

This paper discusses the planning and eventual field application of such an optimised mud programme for a second appraisal well on an onshore Papua New Guinea field. From offset and previous well data, it was realised that the correct choice and optimised engineering of the mud system was of primary importance to the success of the project. The trial proved extremely successful with a large reduction in drilling days, elimination of balling, reduction in the occurrence of swelling and sloughing shale, elimination of stuck pipe and excellent dilution rates thereby reducing the volume of mud materials required in such a remote location.

The paper outlines the laboratory assessment of the chosen fluid, provides detailed field performance review with comparison made with previously used drilling fluids and discusses the mechanisms which resulted in such improved performance over other water based muds.
Rheologically Stable Deepwater Drilling Fluid Development and Application
Authors: Elward-Berry Julianne , Thomas E. W.
Published: December 2007

In offshore deepwater drilling, the drilling fluid should be selected to inhibit the formation of gas hydrates that could plug the BOP stack in the event of a gas kick. However, at water depths in excess of 4000 ft, the concentrations of salts and polyalcohols required for hydrate inhibition make it difficult to achieve stable drilling fluid properties, particularly rheological control.

Laboratory development of stable drilling fluids in such media required modified testing procedures to confirm fluid stability over the cooler operating temperature range. Field experience with drilling fluids that were required for wells in water depths of 4356 ft and 4645 ft is reviewed. The use of a dewatering system to recycle the expensive aqueous phase, and the use of a chloride measuring instrument for consistent and accurate concentration values are described.
Improving Drilling Performance through Continuous Operations - A Worldwide Study
Authors: Hinkel R. M. , Bush G. S. , Bell R. A.
Published: December 2007

This paper presents detailed evidence of performance improvement and cost reduction in drilling projects with continuous operations. The data includes drilling performance curves from major programs in different locations worldwide. The discussion focuses on the major parameters that contribute to learning curve development, or continuous improvement with time in the drilling operation, including:

continuity and similarity of operations simplification of operations incentive contracting performance management technology application

The data presented in this paper demonstrates conclusively that progressive improvement, of up to 75% over a five year program, in the drilling operation can be achieved through continuous drilling programs that are properly planned, engineered, and managed, without sacrifice to operational safety and prudent operating practices. The authors realize that many of the discussed factors reflect good common sense and sound operating practices, however, we have found that it is crucial that all factors be prudently applied for total optimization of drilling performance.

The paper also emphasizes that optimization of drilling performance and the elusive "win-win" ideal for both operator and contractor can only be achieved through continuous operations. Properly managed, continuous drilling operations provide both operator and contractor a long term, vested interest in improving drilling performance.
Drilling a Blind-Entry 4,000-ft Horizontal Well in a Depleted Sandstone Reservoir
Authors: Beardmore D. H. , Gent J. L. , Esbaugh R. A.
Published: December 2007

Phillips drilled a 4000' horizontal oil well at 6048' true vertical depth in a depleted (1 Ib/gal equivalent mud weight) sandstone reservoir in Caddo Co., Oklahoma, to combat gas coning problems. Seven external casing packers were set in the slotted liner for production control. Initial production from the well was 1800 barrels of oil per day (BOPD) with little gas.
Unique Roller Cone Bit Design Improves Economics of Soft Formation Drilling
Authors: Isbell M. R. , Besson Alain , Torgerson T. A.
Published: December 2007

Until recently, long intervals of homogenous, low compressive strength formations were most economically drilled with steel tooth or PDC rock bits. Conventional tungsten carbide insert (TCI) bits were generally too slow to be competitive.

The TCI bits developed for increasingly softer applications have been highly successful in terms of increasing penetration rates with longer life. Even so, PDC and steel tooth bits still dominate the softest drilling, leading to an effort to develop a softer TCI bit. The result is a novel cutting structure engineered for soft shales and sandstones. This premium package, featuring irregular insert spacing and arrangement with optimized hydraulics, has dramatically improved the economics of TCI bits. The aggressive TCI cutting structure drills soft formations with the penetration rate of sharp steel tooth bits and the durability of conventional TCI bits.

This paper describes the design criteria and development of the new cutting structure, which was specifically designed to drill faster and longer than the conventional TCI bit and multiple steel tooth bits in soft formation drilling programs.

The design effort included full-scale simulator tests of steel tooth and TCI bits in both new and dull conditions to define and quantity key performance characteristics and to measure the improvement of the new design. The new IADC class 417 design was successfully field tested in a variety of applications, including directional drilling. Field tests have shown this new cutting structure to be a premium tool for high-speed drilling long intervals of low compressive strength formations.

Analysis of field performance shows significant improvements in ROP, bit life, and drilling costs. Case studies of drilling applications in the Gulf Coast, South America, and the Asia Pacific region show the success of the new design.
A Quality Approach to Safety Management
Authors: Fitts T. G.
Published: December 2007

Safety systems typically produce inconsistent results. Erratic safety performance promotes anxiety in the boardroom and skepticism on the shop floor. This paper presents a quality approach to safety management that will produce a more consistent level of safety performance. The system can be measured, continuously improved, implemented anywhere in the world and utilized as a foundation upon which to establish partnerships between client and contractor.
Quality Systems: A Software Approach
Authors: Brooks K. C.
Published: December 2007

It's a given that the concept of Quality is having a major impact in the petroleum arena today. More and more companies realize that in order to do business in Europe and other parts of the world, a focus on quality has to become an integral part of the company's culture. This paper will look at an innovative approach to Quality Systems through the use of a custom software system which governs the major elements of the ISO 9000 standard for quality.
Sensitive Biological Habitats and Resources in the Gulf of Mexico: Environment Issues and Concerns for the Regulation of the Petroleum Industry
Authors: Avent R. M. , Rogers R. M.
Published: December 2007

The Minerals Management Service (MMS) has oversight for leasing, exploration, and development of mineral resources on submerged Federal lands on the U.S. Outer Continental Shelf (OCS). The MMS Environmental Studies Program was initiated in 1973 to provide a management information base in support of oil and gas operations activity on the OCS. Some of the environmental issues in the Gulf of Mexico relating to biological and habitat resources of special concern are discussed here. These include "live-bottom" habitats, coral reefs, "pinnacle trends," submerged banks, seagrass beds, deep-water chemosynthetic communities, and protected species. Described here are the reasons for concern, including legal mandates and special environmental significance, and governmental action taken.
Bottomhole Assembly Design and Response on Statfjord CO2 Extended Reach Well
Authors: Tjoetta Helge , Blikra Harald , Hardman Paul , Gibbins Chris , Skjelvik Håkon
Published: December 2007

Well 33/9-C02 with its horizontal Teach of 7290m is a new world record in extended reach drilling The well was drilled from the Statfjord C platform in the Norwegian sector of the North Sea and has a total length of 8761m. The partnership established between the operator and the service company was key to the development of a successful directional drilling strategy. This paper examines bottomhole assembly design and performance in the key sections of this technically challenging well.
An Automated System for Predicting Drilling Performance
Authors: Whelehan O. P. , Thorogood J. L.
Published: December 2007

Drilling time is a major component of well cost. Accurate time forecasting is thus a prerequisite to effective performance analysis aimed at systematic improvement. This paper describes a novel time forecasting system based on a detailed and coherent model of drilling time which underlies daily reporting, performance analysis and forecasting. The methodology has been automated in a drilling information system providing engineers with a powerful analysis tool on their desktops.
Gas Kick Simulation Study for Horizontal Wells
Authors: Wang Zhihua , Peden J. M. , Lemanczyk R. Z.
Published: December 2007

This paper presents a gas kick simulation model for horizontal and conventional wells. The model is based on the solution of the appropriate mass and pressure balance equations. The unique aspect of this model is the coupling of the fluid flow in the horizontal section with the gas influx from the formation. Two particular kick control scenarios are presented. The simulation results demonstrate that the actual horizontal drilling situation, actions taken immediately upon kick detection, and operations during kick development all have an effect on the development of the kick profile along the wellbore, which in turn has significant impact on the pressure build-up during the shut-in period and the subsequent kick circulation operations.
Analyzing and Understanding the Underground Blowout
Authors: Grace R. D.
Published: December 2007

The underground blowout can be the most difficult, dangerous, and destructive situation in well control. If the blowout is shallow, cratering can result and endanger the lives of all involved. The underground blowout is often denied since the usual manifestations of a blowout is hidden from view. It is imperative that the blowout be recognized and diagnosed as soon as possible. This paper examines actual case histories of numerous underground blowouts. The techniques used to understand the blowouts are presented. Specifically, analyses of surface pressures, temperature surveys, and noise logs on these specific blowouts are presented and discussed.

The paper illustrates how the analyses of surface pressure data and temperature surveys are very definitive in understanding the underground blowout. In the cases studied, the noise log interpretation is shown to be confusing and inconsistent.
Innovative Advances in MWD
Authors: Martin C. A. , Philo R. M. , Decker D. P. , Burgess T. M.
Published: December 2007

At the 1991 SPE Forum on MWD, participants expressed the need for more reliable tools, higher data rates and lower cost operations. This paper describes the efforts of one service company to meet those needs.

A new tool was specified to meet a goal of 1000 hours Mean Time Between Failure (MTBF). Significant improvements in tool reliability have been achieved through a combination of new design, simplified maintenance procedures and operating practices. Innovative design features of mechanical and electrical components, including system testing, have nearly eliminated failures associated with manufacturing. For the first time in the industry, this tool can communicate with other downhole components through the use of wireless telemetry. This gives the ability to place other drilling tools between the MWD pulser and other measurement tools. The operating range of the tool has been extended to 175°C to be able to perform in high temperature wells. New technology has helped simplify maintenance procedures.

The recent increase in the number of downhole logging measurements, and the development of geosteering techniques, have resulted in a need to increase the real time telemetry data rate so that geologists and petrophysicists can have access to higher resolution logs in real time. An order of magnitude improvement has been achieved by a combination of new design features and data compression.

Operating costs have been reduced by:

– improved reliability which minimizes trips to change failed tools – increased data rate which means that high resolution resistivity and porosity logs can be achieved in real time at faster penetration rates – two-way communication which means that the operator can switch focus from drilling mechanics to formation evaluation without tripping to change the tool – significantly reducing downtime through innovative processing which enables directional surveys to be made while rotating

Field examples are shown from N. America and the North Sea which illustrate these points.
Improvement in Drilling Efficiency With Performance Power Head Section Motors
Authors: Dugas J. J. , Califf B. C. , Chappell J. W.
Published: December 2007

Making better use of available hydraulic power, while improving mud motor life, can result in a significant increase in ROP and reduction in overall drilling costs. This paper shows how the need for improvement in mud motor performance was addressed, using existing, proven technology in a creative new way. A new mud motor design has resulted in a dramatic ROP increase and a significant reduction in operator cost on recent wells in the Austin Chalk.
Orwell Field: Case History of a Low-Cost Subsea Development in the Southern North Sea
Authors: Swale A. M. , Vass Malcolm
Published: December 2007

This paper presents an overview of the development of the Orwell gas field in the UK Southern North Sea. The production of first gas from the field in early August 1993, only 18 months after starting conceptual design and 13 months after receiving UK Government approval, has set a North Sea record in’ fast track developments, and highlighted the benefits of combining existing drilling and subsea technology.
Underbalanced Drilling Through Oil Production Zones With Stable Foam in Oman
Authors: Kitsios Efstathios , Quaresma Vitor , Rovig J.W. , Reynolds Elaine
Published: December 2007

In July of 1992, Petroleum Development Oman embarked on a series of field trials to assess the operational feasibility and commercial benefits of drilling depleted oil production zones under balanced with "stable foam". These trials called for a review of standard well control philosophies and practices, and the incorporation of a flow control concept. Three trials have been conducted, the first in a vertical well and the others in horizontal wells. Two of the trials were performed successfully and productivity results are encouraging. The third foam trial had to be discontinued due to sloughing shales in the horizontal section. More trials are planned to enable the quantification of commercial' benefits.

Introduction

Within several of the existing fields in Oman, reservoir pressures have dropped substantially to levels below the hydrostatic pressure exerted by conventional water based drilling fluids, causing significant fluid filtrate invasion during drilling operations. It is known that fluid invasion into the reservoir can lead to formation damage and well productivity impairment. Furthermore, in some fields like Fahud (fractured carbonate reservoir), the large pressure overbalance during conventional drilling causes lost circulation. When this occurs, water is pumped down the annulus in addition to the water being pumped down the drill string so as to prevent gas influx while drilling.

Typically, for an 800 m 6 1/8" horizontal section in the Fahud field with lost circulation at the start of the section, about 10–25,000m3 of water and 15–25 m3 of cuttings (depending on the extend of overgauge hole) are lost into the reservoir. Consequently, the wells take between 2–6 months to produce back the drilling water and reach peak oil production. It is also believed that this formation damage leads to reduced ultimate oil production.

Fluid and solids invasion into the reservoir can be prevented by drilling at balanced or under balanced conditions. Following a study of air-assisted drilling fluid systems and the development of well control procedures, Petroleum Development Oman conducted three field trials with under balanced drilling through oil bearing reservoirs between July 1992 and September 1993.
Onshore Exploration and Development of California Offshore Resources Through Extended Reach Drilling
Authors: Starzer M. R. , Mount P. B. , Voskanian M. M.
Published: December 2007

Advances in drilling technology now enable the exploration for and development of offshore oil and gas resources without the installation of facilities and wells in offshore marine environments. This paper will discuss the resource potential for California tide and submerged lands (tidelands) and recent trends to develop this potential while providing increased environmental protection using "extended reach drilling" from existing onshore (upland) sites. Investigation of the economic feasibility as well as the regulatory and permitting process in developing California's offshore resources through this drilling method will be presented. A prototype upland extended reach drilling development will be discussed for the South Ellwood Offshore Field, Santa Barbara County. This concept, entitled "Clearview," has been endorsed by the staff of the State Lands Commission, local business groups and is actively promoted by the lessee, Mobil Oil Corporation. The aspects of the Clearview Project which make expanded development of the South Ellwood Offshore Field possible will be reviewed.

This paper will examine past trends that shaped California offshore resource development policy and recent circumstances leading to the support of upland extended reach drilling. Royalty revenue sharing with impacted coastal communities may increase the likelihood of development using extended reach drilling and is presently under consideration by the staff of the State Lands Commission (SLC), the agency responsible for the development of tideland oil and gas resources in California.
An Integrated Approach to Drilling Dynamics Planning, Identification, and Control
Authors: Nicholson J. W.
Published: December 2007

An integrated approach for eliminating or preventing severe drilling dynamics dysfunctions is presented. The method involves drilling dynamic analysis and planning, real-time monitoring, and interpretation and control of tricone bit bouncing, bottomhole assembly (BHA) buckling and lateral vibrations, and stick-slip torsional oscillations, although it is expected that this list will expand as the understanding of drilling dynamics phenomena increases. Several field examples, each resulting in improved drilling performance, illustrate the method. It is recommended that the service industry adopt an integrated approach towards drilling vibration control.
Performance Drilling: A Practical Solution to Drillstring Vibration
Authors: Gallagher John , Waller Mike , Ruszka John
Published: December 2007

Recent research has greatly enhanced the industry's appreciation of drillstring dynamic behaviour but, as is often the case, this work has raised more questions than it has answered. Now that the inherent limitations of rotary drilling are better understood, the search is on for a means of closing the ‘efficiency gap’, ie, the shortfall between the performance levels that should be achievable with sophisticated modern bits and the uncertain, frequently disappointing, results that are seen in the field.

This paper describes how contemporary mud motor technology can be applied to drastically reduce the efficiency gap by the simple expedient of providing the bit with the operating conditions for which it was designed, rather than the harsh and destructive environment imposed by rotary drillstring vibration.
Oil Mud Replacement Successfully Drills South Texas Lower Wilcox Formation
Authors: Hasley J. R. , Dunn K. E. , Reinhardt W. R. , Carter T. S. , Duncan W. M.
Published: December 2007

A water-base drilling fluid treated with a special additive has successfully replaced the diesel oil base muds (DOBM) on a series of wells drilled in the South Texas Lower Wilcox formation. Until recently, a relaxed fluid loss DOBM mud was used in this hole interval because It provided improved hole stability and higher penetration rates at favorable economics. The only problem the DOBM mud did not solve was environmental. The cuttings were coated with oil and high salinity brine and therefore had to be treated before they could be disposed of locally. Efforts to find an environmentally safe DOBM mud replacement have resulted in the development of a special additive for water base muds. It offers a significant reduction in total well cost by increasing the rate of penetration and reducing the mud and cuttings disposal costs.

This paper will discuss the field development and use of this special drilling fluid additive that provides improved performance characteristics when compared to traditional, economic, environmentally safe water-based mud systems. Over 45 wells have been drilled with this new water-base drilling fluid additive. In some areas, the average rate of penetration, including connection time, has increased 30% over the DOBM average. The rotating hours required to drill an interval from 1500 - 3000 feet in length with 14.0 - 16.0 ppg mud have been reduced accordingly. Total well costs have been reduced by 20 percent. The authors provide data on how to optimize water-base mud formulations, special additive maintenance treatments, mud solids management and bit performance utilized on this successful South Texas drilling program.
The Design and Field Implementation of a Drilling Hydraulics Application for Drilling Optimization
Authors: Swanson B. W. , Thorogood J. L. , Gardner Andrew
Published: December 2007

Optimum drilling conditions have to date been determined using either trial and error at the rigsite or by repetitive and time consuming calculations, generally involving a number of different PC based programs. Calculating optimum drilling fluid flowrate conditions to ensure the highest possible penetration rate for example, involves manipulating variables such as drillstring configuration, nozzle diameters and mud properties to satisfy constraints such as the ability to clean the hole, bit specific energy, system pressure distribution and rig capability. This optimization process is ideally suited to automation, however, the number of variables and constraints on the problem requires careful design of the user interface.

This paper describes the development of a Hydraulics and Hole Cleaning Application which combines the use of X-window graphical features in an interface with engineering models that faithfully describe hydraulics and hole cleaning. The application uses the engineering models, derived from extensive research, to provide a rapid assessment of operating parameters such as pump pressure, pressure at the previous casing shoe and cuttings cleaning capacity and provides a graphical summary of this information for comparison with drilling constraints. It thus provides an environment for rapid determination of optimum operating conditions.

Described in the paper are the processes employed to translate the routine drilling engineering task into an application oriented to the drilling engineer in the field. This was largely achieved through the design of the user interface. The paper describes the evolution of a number of the features of the interface from original concepts and specifications which were modified as feedback from field use became available. The structure of the current application is described together with examples of typical field output.
Matrix Stimulation: Automation of Treatment Design
Authors: Mininni Simonetta , Cherri Roberto , Cosenza Giacomo , Tambini Mauro
Published: December 2007

This paper presents a knowledge-based system for designing matrix stimulation operations. The two main points in carrying out such a design are to define the technical/economic objectives to be reached and the injection parameters that optimize stimulation. The system takes into consideration these points and generates a matrix stimulation program that includes treatment, spacer and displacement fluids, operating procedures, equipment, reference injection parameters and, finally, diagrams to evaluate the removal of damage during the execution of the job. Expert knowledge has been formalized and implemented using a built-in-house classification shell. The system, preliminarily validated at company headquarters, has been delivered to the operating districts where it is routinely used. The system is part of a more comprehensive project, called PROGRESS (PRoduction Optimization inteGRated Expert SystemS), aimed at providing a decision support system for well production optimization.
Neural Networks: A New Tool for the Petroleum Industry?
Authors: Ali J. K.
Published: December 2007

Recent advances in neural networks have provided computers (and machines) with intuition - the ability to produce a reasonable result to a problem which is intractable, or unreasonably hard, to deal with by formal logical means. Neural networks can learn complex nonlinear relationships, even when the input information is noisy and less precise. Neural networks have made strong advances in pattern recognition, classification of noisy data, nonlinear feature detection, market forecasting and process modelling. These abilities make the neural network technology very well suited for solving problems in the petroleum industry.

The aim of this paper is to give a synopsis of the areas of petroleum technology in which neural networks have been used with success, and to discuss other potential areas of application. Some of the examples include seismic pattern recognition, permeability predictions, identification of sandstone lithofacies, drill bit diagnosis and analysis and improvement of gas well production. Neural networks technology could also contribute significantly to the analysis, prediction and optimisation of well performance, integrated reservoir characterisation and portfolio management.

Although there has been some advances on the design of optimal network structures, it is still largely an art to determine the best paradigm. The paper highlights key factors in the design or selection of neural networks and the limitations of the commonly used models. It also discusses the use of hybrid expert networks which combine neural networks with rule-based reasoning and fuzzy logic for general decision-making operations.
Functional Integration in Design and Use of a Computer-Based System for Design of Statistical Experiments
Authors: Larsen E. A. , Kristoffersen Steinar , Egeland Thore
Published: December 2007

This paper describes computer science aspects of the design of computational tools for petroleum engineers. Our research is based on three systems. We conclude that while integration may be beneficial, it should not be overdone. The user's interpretation of data should be taken into account before integrations are decided on.
Logging and Perforating Operations Utilizing Coiled Tubing in a 25,000-ft MD, High-Angle Well
Authors: Hennington E. R. , Smith Ian , MacDougall I. D. , Fordyce R. S.
Published: December 2007

A North Sea well has been planned to recover gas/condensate reserves utilising a wellbore drilled to a depth of approximately 25,000’, reaching a maximum hole angle of 78 degrees. A monobore completion will be installed. Coiled tubing has been determined the best option to convey cased hole, electric-line logging tools and to deploy an expendable TCP assembly for under balance perforating. This paper discusses the engineering undertaken to apply proven coiled tubing technology to this difficult completion operation.
The Application of Core and Well Testing to Fracture Acidizing Treatment Design: A Case Study
Authors: Van Domelen M. S. , Gdanski R. D. , Finley D. B.
Published: December 2007

This paper describes the design and evaluation process for a large fracture acidizing treatment performed in a high-temperature (275° F), high-closure stress (8,000 psi), limestone formation. The subject treatment was one of several that were performed in a single gas unit. Well behavior during and after each treatment was used to optimize later treatments.

Core testing was performed to evaluate the formation’s reactivity and to characterize the etching characteristics. A fracture acidizing computer model was used to simulate potential treatment options. Both pre- and post-fracturing pressure buildup tests were performed to evaluate the formation characteristics and measure the success of the fracture acidizing treatment. Treating pressure analysis was also used to evaluate aspects of the treatment such as fluid efficiency and fracture propagation.

There was excellent agreement between the predicted and achieved fracture parameters (fracture length and conductivity as indicated by post-fracturing buildup).

Based upon the simultaneous use of core and well testing, it was possible to identify the areas of improvement for future treatments.
Permeability Determination from Well Logs and Core Data
Authors: Johnson W. W.
Published: December 2007

This paper discusses a methodology for accurately estimating permeability from well log devices, with commonly available core and log data. Core permeability and porosity data are used to identify three or four different hydraulic zones (HZ's) with unique pore structures. Logging tools are selected that show different responses for each hydraulic zone. Multidimensional databases are constructed that relate three or four logging values to core permeability to provide relationships for permeability prediction from logs where core is not available. Predictions are more accurate than with other methods because permeability transforms are provided for each pore type and because pore throat size is considered. Well log permeability estimations derived by this method are used to map permeabilities for improved reservoir simulation models, to improve well test permeability estimation, and to optimize well completions. This technique can be applied in either vertical or horizontal wells.
Hydrocyclone Separation: A Preferred Means of Water Separation and Handling in Oilfield Production
Authors: Stroder S. M. , Wolfenberger E. E.
Published: December 2007

Hydrocyclone technology has been successfully applied to standard oilfield production separation in the North Cowden Deep Field of West Texas. A hydrocyclone was successfully tested as the primary means of water separation for a high water cut electric submersible pump (ESP) well, thereby eliminating the need for expanding the conventional water separation and handling facilities at the recipient battery. This hydrocyclone system was environmentally and economically preferred over conventional systems. A permanent unit has since been installed. With its feasibility proven, the hydrocyclone has countless applications to standard oilfield production separation; its proper use will substantially reduce capital investment for facilities and lower operating expenses for many oilfield leases.
Visualization of Flow Into a Vertical Fracture
Authors: Clark P. E. , Courington T. J.
Published: December 2007

Particle transport in vertical fractures has always been assumed to be controlled by particle settling. Recently, comments have appeared in the literature that suggest that segregation by convection may be more important in a class of fractures where the perforation height is small relative to the fracture height Unfortunately, this proposition has not been substantiated with experimental data or other observations.

In order to test the concept two small slot flow models have been constructed that allow the visualization of flow from a point source into a fracture. To be classified as a point source the height of the fracture must be large relative to the height of the perforations. The models can be used over a wide range of entrance and fracture shear rates. One of the models represents a parallel-sided, uniform fracture while the other contains a non-uniformity below the fluid entrance. Little is known about the effect of non-uniformities on fracture flow especially with non-Newtonian fluids.
Advanced Design and Quality Control Techniques for Acidizing Oil and Gas Wells
Authors: Johnson D. E.
Published: December 2007

Past production results after acidizing treatments on oil and gas wells have been unsatisfactory in many areas due to the use of conventional acid mixtures along with inadequate lab testing and design procedures. This paper presents a means of acid-oil emulsion and sludge testing analogous to downhole conditions which appears to be a key element to effective acidizing designs. This study produces improved techniques for testing, design, quality control, and evaluation of such treatments. Production results authenticate the success of these advanced quality control and design measures.