bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibition and Removal of Low-pH Fluid-Induced Asphaltic Sludge Fouling of Formations in Oil and Gas Wells
Authors: Barker Kenneth M. , Newberry Michael E. 
Published: December 2007

Abstract
Many low pH fluids are used in the Petroleum Industry to treat oil and gas wells. These enclude acid fracs, pickling acid, near wellbore acid jobs and scale inhibitor squeeze chemicals. All of these fluids can cause asphaltic sludge (rigid film emulsion) in some wells that can reduce production of oil and gas, plug a well or oil wet the near wellbore formation by reacting with the asphaltenes or asphaltic resins in an oil. This paper will provide information on how low pH fluids react with asphaltenes or asphaltic resins in oil, explain why the standard test results may be inaccurate in predicting these reactions and present a non-standard method which has been used for a number of years to stop the formation of asphaltic sludge in any well at any iron concentration. Case histories of removal treatment of asphaltic sludge from wells and inhibition treatment will be presented.
Real-Time Interpretation Technology for New Multi-Laterolog Array Logging Tool
Authors: Frenkel Michael A. 
Published: December 2007

Abstract
Real-time array resistivity data interpretation is normally performed by means of 1D radial inversion. Such an approach may lead to errors in thin formations and cause productive zones to be overlooked. In this paper, we propose a novel real-time 2D interpretation technology developed for the new Multi-Laterolog instrument. The technology is based on a new method called Localized Rapid Inversion (LRI). LRI substantially reduces computing time by partitioning the 2D inverse problem into a sequence of 1D problems. In addition, it allows for simultaneous data correction for borehole, invasion, and shoulder-bed effects in the close vicinity of a logging point. This interpretation process is able to run in real-time by relying on a set of pre-calculated look-up tables of tool responses and a hands-off LRI-based interpretation procedure.
The technology is general and applicable to different array resistivity logging instruments. We test it on two complex benchmark models and a case study based on test field data acquired by the Multi-Laterolog tool in Odessa (West Texas). Synthetic and field examples demonstrate the capability of the technology to deliver in real-time high quality results now achievable only with the interpretation capabilities of a log analysis center.
Saving Rig Time and Providing Flawless Execution Utilizing Through-Tubing Milling Intervention With Advancements in Job Planning Guidelines and Technology
Authors: Garfield Garry , Kelbie Graeme 
Published: December 2007

Abstract
Many factors need to be considered when planning a well intervention. In terms of saving rig time and successful downhole milling operations, one critical success factor of milling operations is structured pre-and post-job guidelines. The guidelines may include a structured pre-job information questionnaire, which provides a more accurate picture of the problem and allows for a more detailed and auditable fit-for-purpose solution to the problem in terms of equipment selection, job procedures, and well programming. Without a set of stringent guidelines to assist in detailing the correct tools required for each application, the success of each intervention may not be realized. Through case histories this paper will show that utilizing, appropriate technology, tool designs, and structured guidelines lead to successful through-tubing intervention milling operations in cases when removing multiple composite bridge plugs. Discussion will involve the pertinent information required prior to equipment selection and job engineering and how that information relates to the equipment's performance and overall success or failure of the objectives for the intervention.
Water Shut Off: The Through-Tubing Inflatable Solution
Authors: Kelbie Graeme M. , Garfield Garry L. 
Published: December 2007

Abstract
With continual increase in water production from maturing reservoirs comes the expense of installation of surface handling equipment, disposal and environmental concerns and a reduction in production efficiency from hydrocarbon producing wells. These costs run into millions of dollars every year, dealing with this problem. The operators of these wells have utilized differing technologies and procedures in efforts to control production of these unwanted fluids. Water shut-off applications in one way or another are an everyday part of well servicing work. Some of the methods and practices currently used today to help combat this problem include, placement of cements, plugging back the zone with the aid of mechanical isolation devices, pulling the completion and performing work-overs, and the utilization of purposely designed cements or chemical water blocking agents. Initial efforts to utilize such fluids proved encouraging but methods were required by the operators in order to allow accurate placement of these chemicals. Some of the drivers are;
Economics, in terms of the relatively high cost of such fluids and; The reaction of such water blocking chemicals when placed incorrectly within producing formations and the inability to reverse engineer such misplacements.
Couple these problems with the well geometry to be worked in and the solution of placement can be seen to involve many diverse complications. For this reason the requirement for innovative through-tubing zonal isolation solutions has never been greater. Through-tubing inflatable technology has, for some time now, been providing high-expansion devices in order to provide our industry with an economical and reliable method of isolating and placing water blocking treatment fluids. In this paper we will focus on current inflatable tools that are available today and how they can be utilized to provide cost effective water shut-off solutions at the source of the problem.
Guidelines and Technology for Through-Tubing Milling Intervention That Provide Flawless Execution and Rig Cost Savings
Authors: Garfield G. , Kelbie G. , Wilson S. B. 
Published: December 2007

Abstract
When planning a well intervention, there are many factors that need to be taken into consideration prior to the execution of the operation. Designed guidelines are critical to the success of the milling operations in terms of saving rig time and successful downhole milling operations. These guidelines should include a structured pre-job information questionnaire, provide a more accurate picture of the problem, and also allow for a more detailed and auditable fit-for-purpose solution to the problem in terms of equipment selection, job procedures, and well programming. However without a set of stringent guidelines to assist in detailing the correct tools required for each application, the success of each intervention may not be realized. Through case histories this paper will show that utilizing structured guidelines, appropriate technology and tool designs lead to successful through-tubing intervention milling operations in cases when removing multiple composite bridge plugs. Discussion will involve the pertinent information required prior to equipment selection and job engineering and how that information relates to the equipment’s performance and overall success or failure of the objectives of the intervention.
Well Engineers Deserve a Seat at the Exploration Table: "The Role of Mechanical Earth Modeling in the Early Exploration Process"
Authors: Goodman H. E. 
Published: December 2007

Abstract
Consideration of the full cycle asset development plan from appraisal through abandonment reduces the risk of missed future opportunities due to well systems design constraints. For example, reservoir pressure depletion and subsidence can impact borehole stability to the extent that complex well designs are necessary to fully exploit the asset. Well placement not only depends on the subsiding reservoir section, but also on the reaction of the overlying geological section that must be drilled through to reach the reservoir. For land based operations, the consequences of well complexity may be more easily addressed, the downside being a poor estimate of field recovery that can either rob opportunities for outlying prospects or, in the worst case, cause the asset to be uneconomic. For major capital projects (MCPs) such as deepwater subsalt fields, the capital outlays are immense, with single wells costing up to $100,000,000. For these deepwater MCPs, fewer wells are required to produce reliably for longer periods of time.
The capability to characterize rock mechanical properties from the standard P-wave acoustic data sets, either seismic or open hole log derived, enables well planners to link the Explorationist and Well Engineer’s visions using mechanical earth modeling technology. The accurate assessment of formation rheology, or stiffness, and architecture (distribution and structure), allows the asset team to optimize well systems design, considering placement and production management practices over time.
The presentation will introduce acoustics based rock mechanics concepts, describe the acoustics based rock property prediction technique, and present field applications that demonstrate the impact of the subsurface model to the corresponding well systems design.
A Field Study Optimizing Completion Strategies for Fracture Initiation in Barnett Shale Horizontal Wells
Authors: Ketter A. A. , Daniels J. L. , Heinze J. R. , Waters G. 
Published: December 2007

Abstract
The Barnett shale is an unconventional gas reservoir that is currently estimated to extend over 54,000 square miles. In an effort to improve well economics and to reduce the number of surface locations in populated areas, there has been a rapid increase in the number of horizontal wells being drilled and completed. With this change in development strategy, operators and service companies alike have had to search for innovative solutions to overcome challenges faced in horizontal completions.
Inefficient fracture initiation is the largest reoccurring problem seen when completing horizontal Barnett shale wells. These difficulties are manifested as high fracture initiation and propagation pressures, which lead to low injection rates and high treating pressures. These losses reduce the efficiency of proppant placement and stimulation. As drilling activity has increased over the past couple of years, fracture initiation problems have represented a substantial source of expense and downtime.
This field study examines 256 horizontal Barnett shale wells in an effort to identify the causes of these near-wellbore issues and to offer corrective solutions for future completions. The goal of this study is to recommend an optimized completion strategy to minimize these near-wellbore problems, increase stimulation coverage and decrease unplanned completion expenses.
In 2005, 19% of the stages in horizontal wells examined encountered near-wellbore difficulties. This field study inspects the major contributors to fracture initiation, specifically focusing on cemented versus uncemented laterals, horizontal stress anisotropy, perforation strategy, cementing strategy and stimulation design.
The paper offers statistics on which changes have had the greatest effect on stimulation placement. These problems can cost operators upwards of an additional 25% per stage. Using these optimized strategies has reduced the number of stages where fracture initiation difficulties have been encountered by 74%.
A Straight Line p/z Plot is Possible in Waterdrive Gas Reservoirs
Authors: Elahmady M. , Wattenbarger R. A. 
Published: December 2007

Abstract
Field data and simulated models have revealed that in some cases waterdrive gas reservoirs can be mistakenly misidentified using material balance methods as depletion drive gas reservoirs causing a significant overestimation in gas reserves.
The famous straight-line plot of p/z vs. Gp has been traditionally used to estimate original gas in place (and gas reserves) for depletion-drive gas reservoirs. A gas reservoir in contact with an aquifer in transient phase (unsteady-state) and producing under a certain production schedule can plot as a straight-line on a p/z plot masking the existence of an active aquifer and causing a significant overestimation in gas reserves.
The authors in this paper simulate synthetic cases of gas reservoir/aquifer models using a forward model and an inverse model that were programmed in visual basic to show that the combination of certain rate schedules and the unsteady state nature of aquifers can cause a straight-line p/z plot in waterdrive gas reservoirs.
The authors also demonstrate that the Havlena-Odeh1,2 Plot (also known by some authors in the liteariture as the Cole3 Plot) for those same cases will also mask the existence of an active transient aquifer giving the same value of overestimated origianal gas in place (OGIP) as that obtained from the p/z plot.
Permeability Vertical-to-Horizontal Anisotropy in Indonesian Oil and Gas Reservoirs: A General Review
Authors: Widarsono B. , Muladi A. , Jaya I. 
Published: December 2007

Abstract
Reservoir rock heterogeneity is an ever-present occurence in most reservoirs. One among reservoir properties that are the most affected by its presence is permeability. In most cases, reservoir rock heterogeneity causes permeability anisotropy or variations in permeability with directions. As most theoretical bases used in many aspects in petroleum engineering (e.g. waterflooding, well completion, well productivity, well stimulation, and reservoir simulation) are developed under an assumption of homogeneous reservoir rocks, this permeability anisotropy certainly imposes a special problem that needs to be dealt with.
Indonesia's geological setting is characterized by its high level of complexity. Permeability anisotropy in Indonesian reservoirs varies very widely, and careless approach in picking values representing the level of heterogeneity for individual reservoir may lead to various problems. This paper presents results of a study on permeability anisotropy - in this case vertical-to-horizontal anisotropy - in Indonesian reservoirs through the use of core analysis results. The study involves 14,634 core samples, of which 6,689 are pairs of vertical and horizontal plug samples and 1,256 are full-diameter core samples. They are taken from 259 wells representing 157 fields in all 15 Indonesia's productive sedimentary basins to date. The core samples cover a wide lithology spectrum from sandstones to various limestones.
The study that is carried out through a series of classifications and comparisons has indeed shown the complexity as expected, even though differences can still be distinguished among groups of classification. Evidence has also been observed that results for sandstones and limestone/carbonates core samples as two lithology groups are significantly different even though there are also differences among either group. One very important lesson that can also be drawn from this study is a reconfirmation upon the common opinion suggesting the requirement of a careful study for individual reservoir before adopting KV/KH values for the reservoir of interest.
Smart Fields—Making the Most of our Assets
Authors: de Best Leo , van den Berg Frans 
Published: December 2007

Abstract
Intelligent wells and Smart Fields concept have recently been applied in some assets Shell as a solution to increase production, reduce deferment and increase recovery. Smart Field can however only be fully utilized if the three main elements fully integrate, technology, process and resources.
However Smart Fields is not only about automation. It is about making available the three key ingredients needed to efficiently operate any piece of equipment: reliable performance data, an integrated suite of tools to turn these data to information and operational advisories and a cadre of appropriately skilled professionals that use the information to make the right decisions.
Chayvo Field, Sakhalin Island, Russia: Identification of a Significant Oil Leg from 3D Seismic and Execution of a World Class Extended Reach Drilling Program
Authors: Apotria Ted G. , Mathis Randall S. , Powell Richard J. , Venner Bridget A. 
Published: December 2007

Abstract
In 1997, the ExxonMobil operated Sakhalin I Consortium acquired a 3D seismic survey over Chayvo Field, located off the northeast coast of Sakhalin Island, Russia. At the time of the acquisition, Chayvo was thought to contain primarily gas given the results of five pre-existing crestal wells. Interpretation of 3D seismic revealed seismic amplitude anomalies that conformed to structural spill, were down dip of gas accumulations seen in crestal wells, and indicated the potential for very large, previously unrecognized oil rims. Based on the 3D seismic interpretation, an appraisal well was drilled in 2000 that penetrated several large oil legs. This appraisal well and associated sequence stratigraphic studies resulted in a significant oil project in a field previously thought to be mostly gas.
When the oil rims were confirmed, the challenge was how to develop the Chayvo field lying 8 to 10 kilometers offshore. Development drilling at the field began in 2003, with the first phase comprising a series of extended reach wells drilled from an onshore location reaching offshore to the western limb of the Chayvo anticline. These wells are technically complex and very expensive, but attractive considering offshore platform costs in a remote, environmentally sensitive location characterized by seismic activity and pack ice in the winter.
In 2002, a multi-disciplinary team was assembled to address the challenges associated with designing and executing extended reach wells in stacked deltaic reservoirs comprised of prograding clinoforms. The primary geological concern was the accuracy with which the horizontal well bores could be placed within the oil column, as reservoir simulation indicated the need to be within 10 m of a specified vertical depth. Ongoing drilling has proven to be successful with actual reservoir depths within a few meters of prognosed depths at well reaches of 9-11 kilometers, underscoring the value in the integration of seismic interpretation and extended-reach well planning in a 3D visualization environment.
Pushing the Envelope for Production Logging in Extended Reach Horizontal Wells in Chayvo Field, Sakhalin, Russia-New Conveyance and Flow Profiling Approach
Authors: Fitz D. E. , Guzmán-Garcia Angel , Sunder Ram , Billingham Matt , Smolensky Vitaly 
Published: December 2007

Abstract
Production logging and flow profile interpretations are necessary to properly assess completion performance and interpret pressure buildup data in Chayvo Field. With a lateral reach in excess of 8 km, acquiring production logging data is difficult. Memory logging, with conventional production logging tools via coiled tubing and a hydraulic tractor, was employed. However, due to the wear experienced by the coil, high cost, and poor data quality at low flow rates, this technique was abandoned after initial logging efforts.
Development of a state-of-the-art electrically powered tractor, combined with new surface read out array mini-spinners and optical gas and array resistivity water holdup sensors, provided a viable logging alternative with a 40,000 ft cable specifically manufactured to avoid splice induced weakness. This new logging technology detects and measures stratified flow and lower flow rate fluid entry than conventional axial symmetric production logging tools in ERD well bores. The equipment has recorded production logs to a measured depth of 9,775 m at a true vertical depth of 2,613 m.
Comparison of cumulative flow rates from the array mini-spinner analysis to the logging-while-drilling derived cumulative permeability-thickness product has enabled the evaluation of the completion methodology. Based on the production log analysis, the new completion methodology appears to have restricted flow from the higher permeability intervals while permitting flow from lower permeability intervals. The methods used to plan and execute these production logging programs, and the integration of the interpretations into the pressure-transient analysis for the complex completions of multi-layered reservoirs, are discussed. Examples illustrating data quality and interpretation are provided.
Infill Drilling—Rig Time Optimization in the Gulf of Thailand
Authors: Yingvorapant Worawit , Christieson Richard 
Published: December 2007

Abstract
To meet increasing gas demands while drawing from the shrinking reserves of a mature field, CTEP (Chevron Thailand E&P) is drilling as many wells as economically feasible. Wells have to be drilled and completed very quickly to minimize rig time and reduce the "per well" drilling cost. In 2005, the average time to drill and complete a slimhole well was 6 days; the target for 2006 is 4.5 days.
During 2005, CTEP drilled and completed over 300 wells while 450 wells are planned for 2006. In addition to exceptional drilling performance in the Gulf of Thailand, value creation is enhanced by performing a high number of IFDP (in-fill drilling projects) whenever possible. This reduces cost by minimizing new platform construction, reusing slots, and reducing installation of new surface casing. The IFDP project can be categorized into two phases: (1) slot recovery; and (2) drilling. This paper focuses on phase 1 of the project, where CTEP uses HWO (hydraulic workover) systems along with cementing, slickline, and wireline services to perform the slot-recovery operations before rig arrival. Topics of discussion include current operational equipment, methods and procedures, logistical challenges, lessons learned, and new development plans intended to further enhance the operation.
Statistically, it is estimated that for each single platform 6-well abandonment campaign, CTEP gain 7 to 8 days of drilling time by not utilizing rig time for the Phase I operation. The drilling rig focus is, therefore, maintained on, doing what it does best, drilling new wells safely and economically. Additional wells are drilled with the time saved supplying early gas to meet Thailand's expanding industrial demands.
Case History of One-Trip Monobore Completion System—2 Years of Cement-Through Monobore Completions in the Gulf of Thailand
Authors: Chapman Walt 
Published: December 2007

Abstract
This paper will discuss a Monobore one trip cement through completion system. The system was designed to add artificial lift capabilities and improve safety to short life monobore wells. The disposable well bore concept is gaining popularity in regions worldwide. This paper will also discuss case histories including operation issues and problems and how they were solved.
Operational procedures will be outlined to effectively demonstrate, and discuss the decision making process when determining the most cost effective candidates for this technology.