bluuebunny/crossref_metadata_2025_split huggingface dataset:
First Deepwater Application of Dynamic Annular Pressure Control Succeeds
Authors: Roes V. , Reitsma D. , Smith L. , McCaskill J. , Hefren F. 
Published: December 2007

Abstract
Shell Exploration and Production successfully deployed an automated bottom hole pressure control system developed by Shell International R&D called Dynamic Annular Pressure Control (DAPC) to solve lost circulation and hole instability problems in a deep water Gulf of Mexico well on the Mars Tension Leg Platform, after two failed sidetrack attempts. Dynamic Annular Pressure Control is a system designed to apply controlled annular surface pressure, with the goal of maintaining constant bottom hole pressure. Bottom hole pressure (BHP) can be maintained at any desired over/under balance by use of a lower mud weight than typical, and adjustment of surface backpressure as the circulation rate is varied.
In Shell's maturing deep water developments, rock stress redistribution due to reservoir depletion is causing drilling problems on a scale not seen in the past. High mud weights are still required for hole stability, but reduced fracture gradients have been observed both in reservoir and non-reservoir rock. DAPC was used in the third attempt to sidetrack the Mars A- 14 well, to keep Equivalent Circulating Density within the shrinking pore pressure / fracture gradient window.
The DAPC system was fabricated, installed and tested on a fast track basis after a review of the technology indicated a high likelihood of enabling the well to be drilled without problems. Cased hole tests indicated that BHP could be maintained within the required limits. The mud weight was reduced for the problematic section, and the well reached planned total depth without experiencing lost circulation or hole instability problems. The production liner was run and cemented without incident.
DAPC has been demonstrated as a promising new tool to solve drilling problems associated with reservoir depletion. As the technology matures, it has the potential for broad application to effectively widen the pore pressure / fracture gradient window in deep water, HPHT, extended reach and other challenging drilling environments by continuously and automatically maintaining a desired bottom hole pressure.
A New Industry Standard To Measure Rheology of Completion Fluids
Authors: Asadi M. , Penny G. S. , van der Bas F. , Brannon H. D. , Hawkins G. W. , Lord D. L. , McElfresh P. M. , Milton-Tayler D. 
Published: December 2007

Abstract
A new technical standard is developed to measure rheology of completion fracturing fluids. This method details step-by-step procedure for making fluids and rheology measurements. Completion fluids are defined for the purpose of this technical standard as viscosified treating fluids used during the completion or workover of a petroleum or natural gas producing well. The objective of this technical standard is to provide a standard procedure for measuring the viscous properties of single-phase, non-particulate-laden completion fluids. These fluids are viscosified brines, gravel pack carrier fluids, and fracturing fluids. These fluids can be either crosslinked or non-crosslinked (aqueous, hydrocarbon, or acid based). An optional shear history simulation procedure is provided for fluids that are potentially shear-sensitive. This procedure is designed to simulate the shearing effects experienced by a fluid in surface apparatus and during the time it is being conveyed down the wellbore.
A Compact Compensated Resistivity Tool for Logging While Drilling
Authors: Macune D. T. , Flanagan W. D. , Choi E. , Marcellus E. 
Published: December 2007

Abstract
A new method and tool design for borehole compensated electromagnetic propagation resistivity logging while drilling (LWD) are presented. The method provides borehole compensated resistivity measurements at multiple depths of investigation using a shorter antenna array than existing compensation methods. The compact array is typically 40% shorter than conventional antenna arrays for borehole compensated measurements, resulting in a shorter, lower cost bottom hole assembly (BHA). This paper presents the theoretical basis of the compact array design, as well as electromagnetic modeling results demonstrating performance in downhole conditions of interest. Results from field tests of a downhole tool are also presented.
The compact array design has been applied to create a shorter, lower cost resistivity logging while drilling collar. The three resistivity measurements enable determination of true resistivity (Rt), diameter of invasion, and flushed zone resistivity (Rxo) while drilling, geosteering, and formation evaluation in horizontal or deviated wells where application of wireline tools is difficult. The initial downhole antenna array design is some 44% shorter than equivalent conventional antenna arrays for borehole compensated measurements.
Electromagnetic modeling results are presented for the three-receiver and two-transmitter antenna array to demonstrate performance of the shallow, medium, and deep resistivity outputs from phase-difference measurements. Modeling and field test data are used to show equivalent performance of the compact array to existing compensated antenna arrays in rugose boreholes and at bed boundaries. Modeling results are also presented which demonstrate the limitations and advantages of multi-frequency operation. Test data for a new method for compensation of electronics error are also shown.
The paper presents a new approach to LWD borehole compensated resistivity methods that reduces the overall length of the antenna array and associated cost. The compact antenna array provides improved invasion profiling and determination of true resistivity when compared to existing borehole compensated array designs.
Worldwide Field Applications of a Polymeric Gel System for Conformance Applications
Authors: Eoff L. S. , Dalrymple E. D. , Everett D. M. , Vasquez J. E. 
Published: December 2007

Abstract
Water production becomes a major problem as hydrocarbon producing fields mature. Higher levels of water production result in increased levels of corrosion and scale, increased load on fluid-handling facilities, increased environmental concerns, and eventually, well shut-in (with associated workover costs). Consequently, producing zones are often abandoned in an attempt to avoid water contact, even when the intervals still retain large volumes of recoverable hydrocarbons. Many polymer systems have been applied over the years to control undesired water production from hydrocarbon wells, with varying degrees of success.
For approximately eight years, a polymer system based on an acrylamide/t-butyl acrylate copolymer (PAtBA) crosslinked with polyethyleneimine (PEI) has been used successfully for various water shutoff applications. This paper will describe results from a sampling of over 200 jobs performed throughout the world, including the average results from over 90 jobs performed in one geographic location alone. In addition to "standard" matrix treatments, results will be shown for other types of treatment, including a design to plug annular communication and a combination of sealant and temporary gel in an openhole horizontal completion. In addition, laboratory data pertaining to work aimed at increasing the temperature limit of the system will be presented. The upper placement temperature of the system originally was ~260°F. Data presented in this paper indicates the development of a retarder system that allows the upper placement temperature to be raised to at least 350°F.
Ultralightweight Cementing Technology Sets World Record for Liner Cementing With a 5.4 lbm/gal Slurry Density
Authors: Kulakofsky D. , Paredes J. L. , Morales J. M. 
Published: December 2007

Abstract
In an effort to meet increased demand for petroleum products, operators are drilling in more challenging environments. In Mexico, meeting the new challenges is requiring more skills and innovative materials from oilwell cementing providers. Nowhere else in the world have service providers attempted cementing across more depleted zones or weaker formations. Current cementing technology may not ensure successful circulation and an effective seal, which can have a great impact on (1) the cost of drilling a well and (2) the productive life of the well. In addition to the easily quantified cost of often-required remedial work, additional costs that are more difficult to quantify can be incurred from delays in production delivery and early water production.
Traditionally, the industry has relied on two very different technologies for the creation of ultra-light (densities &lt; 10 lb/gal) cement slurries. The current technology involves either (1) the creation of a foamed cement using nitrogen or (2) the addition of lightweight microspheres (LMS) (sg &lt; 1.1) into the cement. While both of these technologies are capable of producing very light cement slurries, neither of them has been used in an oil well to form an effective seal at densities below 7.3 lb/gal. In these most difficult Mexican formations where fracture gradients range from 7.3 down to 6 lb/gal, current cement densities of 7.3 lb/gal or greater have reduced chances of successful circulation.
This paper presents case histories from Mexico showing how a melding of both of these technologies, foam and microspheres, were required to stretch current lower slurry-density limits, allowing us to meet extreme operational demands. Along with the case histories and laboratory data, guidelines are provided for the best use of these technologies at densities down to 5 lb/gal. Details provided from the case histories illustrate how the advantages of both technologies were maximized, while their limitations were minimized.
Employee Violence Risk Assessment
Authors: Kuo W. H. 
Published: December 2007

Abstract
Perhaps the worst nightmare of any supervisor is dealing with an employee who is violent. Nevertheless, before there is an actual violent episode, or a serious threat of violence, there are background information, past history, and behavioral clues to forewarn a supervisor of an impending event. Applying current forensic psychiatry knowledge, this paper provides supervisors with useful tools to recognize early warning signs for risk assessment.
Perforating an HP/HT Gas-Condensate Reservoir Overbalanced in Oil-Based Mud
Authors: Svela P. E. , Wennberg K. E. 
Published: December 2007

Abstract
Kristin is an HPHT gas condensate field which presents challenges at all levels. At present no solution is ready with regards to drilling in depleted reservoir, which means that most wells have to be drilled before production start. This results in a very limited production experience (well test at low rate) between the completion of each well.
Initially the Kristin field was planned completed using a stand alone screen solution and cesium formate based drilling and completion fluids. However it soon became clear that an additional completion solution and an alternative completion fluid needed to be evaluated.
Due to operational constraints overbalanced perforating was the only feasible solution and work was started to qualify a fluid system for this use. Different drilling fluids had already been tested for formation damage with regards to screen completion, and from this selection an oil based mud and a cesium formate based mud was chosen for further testing with regards to perforating. This testing was performed on an analogue rock to the Kristin reservoir emphasizing on rock strength and permeability as key indicators.
The preferred fluid was found to be oil based mud, and this fluid was recommended as perforating fluid for the first well to be perforated in the Kristin field.
Well 6406/2-R-3 H was perforated overbalanced in 2.06 sg oil based mud, April 2005 and subsequently cleaned up towards test equipment on the drilling rig.
This paper describes the work done to prepare and qualify a suitable perforating fluid for HPHT conditions, while trying to minimize damage. Furthermore the results from the test of the first well perforated overbalanced is described.
Integrity Management in KOC
Authors: Esaklul K. A. , Al-Adsani A. M. 
Published: December 2007

Abstract
Any lapses in design or operating practices predominately in the form of departure from the design intent or standard operating procedures have the potential to lead to undesirable events. The resulting design or operating deficiencies once recognized are usually mitigated by add-on safety features, robust practices, effective training and efficient emergency plans; orelse passively by incident investigations. All of which fall under an Integrity Management System.
Effective Integrity Management Systems are assessed through performance indicators that measure accountability and ownership and the mitigating measures effectiveness (individual programs and the management system key elements as a whole). However, even with an effective management system there will always be a dependency on intermediaries and a degree of subjectivity in assessment; therefore there is no replacement for intrinsic safety features and a competent operating workforce.
KOC has recognized that integrity management like HSE is not limited to just mechanical integrity but involves management of hazards, process safety, competency and accountability. To fully address this issue KOC reviewed current industry practices in integrity management and identified the key elements that, if implemented efficiently, will tackle the IM issues within KOC. An IM standard defining Integrity Management and comprising eleven elements has been developed and is in the process of being implemented. The IM elements address risk assessment, hazards evaluation, development of risk management plans, implementation of the risk management plans and capturing lessons learnt to continuously improve.
Delivery of the IM initiatives will take time but like HSE, IM is a continuous journey for the life of the company and the outcome will be rewarding both in increased production, safe operation and committed competent workforce.
Introducing a Total Waste Management Program
Authors: Lawrie G. , Forbes D. 
Published: December 2007

Abstract
In 2001, Schlumberger (SLB) decided to develop and introduce a total waste management system. Rising quantities of landfill waste were deemed unacceptable. Not only did the global quality, health, safety, and environment (QHSE) policy state a goal of "no harm to the environment," but also landfill waste disposal costs had more than doubled in the last 10 years and were predicted to treble over the next 10 years.
The single-source waste management program integrated the following tasks: interceptor maintenance, hazardous waste disposal, dry waste disposal, tank cleaning, industrial cleaning, recycling, sampling and analysis of interceptors and separators, waste reporting, consultancy and advice, oil and chemical spill response, confidential disposal service, and regular review meetings. The improved segregation of waste, awareness of final disposal treatment costs, disposal to landfill, incineration procedures, and recycling (of plastic, wood, metal, glass, white paper, newspaper, toner cartridges, and plastic cups) contributed to significant recycling opportunities as well as reduced the total quantity of waste. The program also offered accurate control and traceability of final waste destination. It created an immediate 25 to 30% cost reduction.
Further benefits included an overall improvement in general housekeeping that reduced health and safety exposure and a general increase in environmental awareness and concern. The employees were very enthusiastic about the program, and it was noted that awareness did not stop at work: the focus switched to home, as more employees actively started to seek out the local recycling depots for waste produced at home.
The program is not unique to one area and is currently being implemented in other locations across the world, including Norway and Abu Dhabi. This paper is designed to share best practices with other oil and gas companies across the globe.
Management of Change—Systems Approach With Applications
Authors: Unnikrishnan G. 
Published: December 2007

Abstract
Process systems are complex structures involving interaction of many components of diverse nature including humans. They are designed and built based on certain specifications and operated for many years. During the course of operation it may see several changes. Any change will have an impact on the operation of the plant. Management Of Change (MOC) is about understanding such changes and trying to control them. In the course of time companies have developed procedures and methods to implement changes so that they are controlled and its effects predictable. History is full of cases that resulted in accidents when such changes were made without adequate analysis.
The paper will examine the basics of current MOC procedures and methods. While they address the particular part or the subunit where the changes are planned, its effect on the overall process system is usually forgotten. Case studies indicate that while everything appeared fine by conventional MOC procedures, the changes did impact the system in a manner not predicted by these procedures.
Many MOC methods cannot assess or predict such impacts simply because it is incapable of doing so. A Systems approach would have predicted such impacts. Such an approach observes the changes as part of a whole system and in helps in understanding how changes can impact elsewhere on a long term basis.
In conclusion the paper will demonstrate that Systems approach will be highly beneficial and can be built into existing MOC practices. To support the same several hindsight reviews of incidents will be presented; incidents which could have been addressed properly, had a Systems approach been taken at the right point of time.
Use of Novel Acid System Improves Zonal Coverage of Stimulation Treatments in Tengiz Field
Authors: Albuquerque M. A. , Ledergerber A. G. , Smith C. L. , Saxon A. 
Published: December 2007

AbstractBetween December 2003 and February 2005 eight wells were stimulated in Tengiz field in Kazakhstan using a viscoelastic diverting acid system to evaluate the effectiveness of this system in achieving diversion and zonal coverage in large limestone reservoirs. The viscoelastic diverting acid system was pumped through coiled tubing in three of these wells and bullheaded in five other wells for comparison between both methods of placement. Pre- and post-job production logs acquired in five wells provided analysis of changes in the production profiles. In one of the wells, the formation was stimulated first with 15% HCl through coiled tubing and then with the viscoelastic diverting acid system bullheaded down the production tubing; production logs were acquired after each treatment.The results from comparison of pre- and post-job production logs clearly show a change in the production profile after the stimulation with the viscoelastic diverting acid system, with a significant increase in production from the least prolific zones.Conclusions from this field trial are that viscoelastic diverting acid systems can achieve full zonal coverage in stimulating large limestone reservoirs, whether conveyed by coiled tubing or bullheaded from surface. The use of viscoelastic diverting acid systems allows oil recovery from the most damaged zones. Oil recovery from these damaged zones was not previously achieved with conventional stimulation methods, owing to the tendency for stimulation fluids to migrate to the most permeable zones. Viscoelastic diverting acid systems are more effective in achieving diversion than coiled-tubing-conveyed methods using conventional linear acid systems.
Optimization of Well Performance in a Selective Subsea Sand-Control Completion, Offshore Nigeria
Authors: Guinot F. , Ezeukwu T. E. , Stenger B. 
Published: December 2007

Abstract
Developing the Okwori field (offshore Nigeria) required the combination of several recent technological advances. The subsea development targeted multiple oil-bearing zones in all wells with the requirement that each zone could be operated independently. Expandable sand screen (ESS) strings were deployed within casing for up to four zones in order to prevent sand production from unconsolidated sandstone reservoirs. Independent control of all zones was made possible by using remotely operated surface controlled sliding sleeve units.
Losses experienced after perforating required the use of loss control material (LCM) for well control. Initial LCM formulation appeared to be damaging productivities. A special effort ensued to design optimal LCM pills with regards to the specificities of this project. This paper presents the completion issues associated with the project, the optimization of the LCM pills, and the design and placement aspect of the remedial treatment associated with this type of completion. The evolution of the completion efficiency for each zone throughout the learning curve is presented and discussed.
High-Viscosity-Yield Acid Systems for High-Temperature Stimulation
Authors: Welton T. D. , van Domelen M. S. 
Published: December 2007

Abstract
This paper discusses the development of a unique in-situ crosslinkable acid system that uses a blend of HCl/formic acid as the base acid and a synthetic polymer gelling agent. The ability to in-situ crosslink an organic acid blend is novel. In addition, an unexpected result of the fluid development was the discovery of its unique rheological properties.
Historically, both gelled and in-situ crosslinked acids have been used for fluid loss control during fracture acidizing and for diversion in matrix treatments in carbonate formations. Various synthetic polymers are used to gel the acid. Past research indicates that ~20 cp base gel viscosity is required as the first step in fluid loss control. In-situ crosslinking allows very high viscosities to be generated as the acid spends. The crosslinked gel creates a permeability barrier and subsequent fluid stages are diverted to other sections of the zone. When the acid fully spends, the gel breaks, giving a low viscosity fluid.
HCl is the most common base acid used for carbonate stimulation. Combinations of HCl and organic acids have been used because of their high dissolving power and relatively low rates of corrosion at elevated temperatures. In extreme cases, combinations of organic acids are used. While HCl/formic acid blends have been utilized in the past, the unique rheological properties of these blends have not been fully explored.
The chemistry and rheology of gelled and in-situ crosslinked HCl/formic acid blends equivalent to 28% HCl will be described and compared with traditional gelled acid and in-situ crosslinked acid.