bluuebunny/crossref_metadata_2025_split huggingface dataset:
Field-Wide Variations of Wettability
Authors: Hamon Gerald 
Published: December 2007

Abstract
Core laboratory results are used to describe the variations of wettability Index and residual oil saturation to water within an oil-bearing consolidated reservoir. Core sampling is carried out to cover a large range of permeability ( from 1 mD to 1600 mD) and height above the initial water-oil contact (from 4 m to 175 m). The following experimental data are available: Twenty-six drainage and imbibition capillary pressure curves are measured at reservoir conditions, using reservoir fluids and both water-wet and oil-wet semi permeable membranes.Quantitative mineralogy and pore geometry by combined SEM and image analysis. Both bulk and pore wall mineralogy is available on some samples.
Typical mixed-wet imbibition capillary pressure curves are obtained. Experimental results illustrate strong trends between the amount of spontaneous imbibition, the wettability Index to water and the residual oil saturation on one hand and both the structural position and the permeability of samples on the other hand. Relationships with pore wall mineralogy are rather weak.
The combined effects of structural position and permeability on wettability result in unusual variations of the forced imbibition capillary pressure curve within the reservoir. The plateau of the Pc curve is weakly dependent on permeability. A new way to extrapolate forced water/oil imbibition Pc curves is proposed.
Emulsion Separation Index: From Laboratory to Field Case Studies
Authors: Kokal Sunil , Wingrove Martin 
Published: December 2007

Abstract
Quantifying oil-water or emulsion separation has always been difficult. This is due, in part, to the numerous factors controlling oil-water separation. This paper describes a new method developed at Saudi Aramco for the quantification of oil-water separation process. It is designated as ESI or Emulsion Separation Index and it was developed to measure emulsion stability. This index has been used to select and screen demulsifiers and to quantify the effect of various factors that affect oil-water separation including temperature, shear, asphaltene content, watercut, demulsifier dosage and mixing different crudes. Its use has eliminated some of the ‘art-work’ associated with demulsifier selection and diagnosing emulsion treatment problems.
This paper also describes three field case studies where the ESI was used to select the best demulsifier, diagnose, and ultimately solve emulsion related problems during oil production. The first field study is from the largest onshore oil field in the world. The emulsions from this field were being stabilized by inorganic scales and organic asphaltenes. The paper describes how the ESI was used to diagnose and resolve the problem. The second field study is from the second largest offshore field in the world. Here extremely tight emulsions were forming and plugging the separation equipment offshore. These emulsions contained 70–90% water and were very viscous. Their deposition in the separation equipment was resolved by using recommended demulsifiers and performing ESI tests in the field. The demulsifier dosage was also optimized using these tests. The third field case study is from another large offshore field that produces from seven different reservoirs. The properties of the crudes from the seven reservoirs vary significantly. These properties provide an interesting case of operational problems in oil-water separation including increased incidents of arcing/shorting in the separator, tripping of equipment and increased demulsifier consumption. The factors affecting oil-water separation were quantified using ESI. The results show a strong correlation of asphaltene content in the crude oil with ESI or emulsion tightness. Recommendations were made for reducing and optimizing demulsifier dosage by adding chemical additives. Many lessons learnt in these field studies are applicable to any crude oil treating facilities.
Unique Multilateral Completion Systems Enhance Production While Reducing Cost and Risk in Middle East Offshore Wells
Authors: Demong Karl 
Published: December 2007

Abstract
Most multilateral wells in the Middle East have been completed as non-access single-selective or limited-access, dual-selective wells. These configurations improved production by achieving increased reservoir exposure at reduced operating cost by hitting two or more targets from a single well. Previous applications had a disadvantage in that these configurations often limited the operator’s ability to monitor and enhance well production or perform effective workover operations. Advances in multilateral (ML) completion technology for new or existing wellbores have now resolved some of these difficulties with unique completion systems. These have the capability to mechanically connect laterals to parent wellbores and allow segregated production and intervention at any time in the life of the well. Operators in Qatar, Saudi Arabia, and the United Arab Emirates have applied these innovative techniques, providing a greater variety of options to satisfy the completion, workover, and intervention requirements of dual producing wells.
This paper will discuss case histories in which dual-segregated completions with and without pressure-isolated junctions were developed and used. The completions were run in both new and existing wells and in both primary well construction and workover scenarios. In each case, the operator’s requirements were satisfied. The success of these multilaterals has broadened the scope of applicability for duallateral completions and workovers.
The new ML concepts offer the following enhancements: Since the completion configuration is dual segregated, it allows segregated production and segregated through tubing re-entry into two reservoirs.New procedures for running the packers into the lateral have been developed. Construction of the pressure-isolated junction can commence during initial completion or during workover operations. This can reduce the cost of the initial completion and reduce some of the risk of debris problems.Dual segregated completions can be installed as part of the initial completion or implemented later during a workover operation. If there are production problems with a conventional completion or a junction leak in a commingled completion, the dual segregated completion can be installed as a remedy that also supports production logging and any rigless interventions that may be required.
Development of a Continuous Permeability Measurement Using Wireline Logging Methods and the Resulting Impact on Completion Design and Post-Completion Analysis
Authors: Kerchner S. , Kaiser B. , Donovan M. , Villarreal R. 
Published: December 2007

Abstract
In the exploration and development of oil and gas reservoirs, one of the most critical parameters to measure or calculate is permeability. The permeability of a reservoir can have a dramatic impact on the initial completion and stimulation design and a significant influence on reserve calculations.
The methods traditionally used today to acquire formation permeability can be expensive and time consuming. These methods include whole corerotary sidewall and percussion corespressure transient analysisproduction history matching.
Obtaining a whole core is risky and can be prohibitively expensive. Acquiring rotary sidewall and percussion cores also carries an inherent risk and is time consuming and expensive. Also, core analyses do not always reflect representative permeability at downhole conditions and provide a small statistical sampling of the zones of interest. The preferred pressure transient method involves a flow period followed by a pressure buildup test, which involves flowback crew and equipment expenses, possible workover expenses for running tubing, and delays post stimulation production to sales. Similar delays are inherent in production history matching.
A continuous permeability measurement obtained through wireline measurements is proposed as an alternative to these traditional methods. This permeability is available immediately and can be used to proactively estimate reserves and initial production and to design and evaluate the effectiveness of various stimulation programs. The most economic design can then be selected.
This paper describes a project undertaken by Conoco and Schlumberger. The project objectives were to develop a field-specific method to reliably estimate permeability using wireline logging methodsdemonstrate how this information impacts economic and engineering considerations related to the hydraulic stimulation programdescribe the importance of knowledge of permeability in post-audit analysesrecommend best-practice guidelines for use of a particular method to obtain permeability.
This paper covers the project methodology, field data collection and interpretation, completion design, execution, and evaluation, and the project well results.
Reinventing the Wheel - Reducing Friction in High-Angle Wells
Authors: Mason Colin J. , Williams Larry G. , Murray Geoff N. 
Published: December 2007

Abstract
Extended Reach (ER) wells have usually been proven the world over to provide an exceptionally cost effective means of field development. For example, in one particular instance, adoption of ER drilling resulted in +/− 50% savings compared with a sub-sea completed well. Additionally, intervention costs were dramatically reduced since the substantial cost associated with mobilizing a "floater" into the relatively remote area was averted (1).
Frictional losses due to torque/drag (T/D) are a primary limitation in extending the reach of many high angle wells. This paper specifically considers T/D problems associated with current well designs and presents roller-based tool technology as a solution for reducing mechanical friction losses.
Also considered are some of the other merits of roller type technology that are not immediately apparent. They include decreased likelihood of differential sticking; an important consideration given the significant 4D seismic created interest in in-fiII drilling. The drilling tools can also have an impact on drilling performance by helping to reduce axial and rotational stick/slip, thus prolonging bit life, increasing rate of penetration (ROP), and potentially avoiding a trip to replace the bit.
Field trial results, case studies and laboratory tests will demonstrate that roller-based tools are an effective solution to combating mechanical frictional losses.
An important point is that since roller-based tools function almost independently of drilling fluid type, they should enable operators to use lower-cost drilling fluids, such as water based muds that comply more easily with local environmental legislation.
CO2 Flood Potential of California Oil Reservoirs and Possible CO2 Sources
Authors: Jeschke P. A. , Schoeling L. , Hemmings J. 
Published: December 2007

Abstract
Carbon Dioxide (CO2) has been used to enhance oil recovery for several decades in both miscible and immiscible floods depending on the type of oil and class of reservoir. Numerous CO2 floods are presently active in four countries with the majority in the Permian Basin of the U.S. where both naturally occurring CO2 and pipeline infrastructure exist and where over 50 million barrels of incremental oil per year are produced. Estimates indicate that additional billions of barrels of oil could be produced in the U.S. alone with CO2 flooding if CO2 could be economically delivered to the producing states' oil fields. California has the second highest potential of any state to produce oil with CO2 flooding but has no naturally occurring deposits of CO2 or CO2 pipeline infrastructure. This paper presents the results of a study of the CO2 flood potential of California oil reservoirs and the possible sources of CO2 for California enhanced oil recovery projects.
Experience of IOR Practices from Large-Scale Implementation in Layered Sandstones
Authors: Wang Demin , Cheng Jiecheng , Li Qun , Jiang Youlin , Sun Yingjie , He Yixin 
Published: December 2007

Abstract
Daqing Oil Field has produced more than 11 billion barrels of crude oil and is still producing at a rate of more than one million barrels of oil per day. In its development, it has extensively implemented numerous IOR methods. The results are very good, total oil production from the IOR methods is more than 700,000 barrels oil per day and it has more the doubled the recoverable reserves of the oil-field (from 8 billion barrels to about 18 billion). Also, much has been learned from the above large-scale IOR practiced, some of which are: The major aim of IOR methods is to increase the volumetric sweep efficiency, displacement efficiency and decrease the water cut (on condition that corrosion, sand, casing damage and environmental issues are not major problems in the field). Results of IOR methods should mainly be measured by a) the total incremental recovery and b) the ratio of the increase in recovery to its costs. To obtain good overall results, large scale implementation on most of the wells in a field is recommended. Otherwise, there will be an increase in production in wells but un-significant increase in recovery of the total reservoir;The results of different IOR methods are mainly dependent on the heterogeneity and water cut of the reservoirs and the IOR method used. Numerical simulation predictions are given and compared to the actual field results. The comparison is satisfactory;For stacked reservoirs, besides horizontal drilling, most IOR methods obtained very good results;For single layer reservoirs, besides chemical flooding and horizontal drilling, most IOR methods were not satisfactory;The reasons that selective water plugging at producers and in-depth profile modification at injectors are not satisfactory and challenges that need to be met are put forward;Criteria for the cost of incremental oil by chemical flooding to be higher, equal or lower than water flooding are put forward with actual field data:The reasons that in-fill drilling of single layer reservoirs can increase the production rate significantly and also the recovery slightly is explained with numerical simulation data and actual field examples.
The above lessons learnt are all from large-scale implementation and numerical simulation, which makes the conclusions more reliable and should be of reference use in the development of layered reservoirs.
Management Overview of the Integrated Studies of Nine Mature Gas Fields in the Cooper Basin of South Australia
Authors: Bard K. C. , Harrison T. , Meade K. 
Published: December 2007

Abstract
In January 1999 Santos on behalf of the South Australian Cooper Basin Joint Venture (SACB JV) began a detailed Integrated Reservoir Study (IRS) of nine mature gas fields in the South Australian Cooper Basin with a team of Santos staff, supplemented by personnel from a Landmark/Fekete/Halli- burton Consortium. The IRS project was to be completed in eighteen months with the following key objectives:

Business

Technical
The studies were to be comprehensive, and were required to include the following: data preparation, petrophysics, geophysics, 3D geological modeling, reservoir engineering, dynamic reservoir simulation, production engineering, drilling engineering, surface facilities and economics, with the final product being a fully documented field development plan for each field. This paper will discuss the key elements to the success of this project.
Modelling Phase Behaviour Including the Effect of Pressure and Temperature on Asphaltene Precipitation
Authors: Kohse Bruce F. , Nghiem Long X. , Maeda Haruo , Ohno Kenji 
Published: December 2007

Abstract
This paper describes a procedure for matching PVT data of a typical oil that includes asphaltene precipitation data. The fluid PVT data are from constant composition expansion, differential liberation and separator test experiments. The experimental precipitation data consist of measurements of precipitation onset pressures at different temperatures.
The PVT data are validated for consistency using Hoffman plots, and matched with the Peng-Robinson equation of state1. A pure solid model is used to model the asphaltene precipitate2,3,4. The equations describing effect of pressure and temperature on the solid model are given. The parameters of the solid model are adjusted to match the asphaltene precipitation data.
Field Application of Multi-Dimensional Diagnosis of Reservoir Rock Stability Against Sanding Problem
Authors: Doi Manabu , Murakami Takahiro , Ueda Yoshiaki , Ohkuma Hiroshi 
Published: December 2007

Abstract
In the studied oil filed, the sanding problems have been recognized to intensify in 1990s when water production has become substantial. It is predicted that water production will increase due to the driving mechanism and its reservoir fluid and rock characteristics. It is important to study and analyze the formation's sand production potential at this stage of the reservoir development, and formulate a sand control strategy in order to optimize the field operation.
In sand prediction, one of the most indicative parameters is UCS (Unconfined Compressive Strength) of reservoir rocks. In order to improve the estimation of UCS profile in the target sandstone interval, we employed a back-propagation neural network which relates the rock strength and well log responses. The errors in the UCS estimation were examined by changing structure of the network, combination of reference well log types, and selection of the actual UCS learning data. Some combinations of the well logs with sonic log generated a high accuracy estimation of UCS data.
Using the UCS data thus estimated, the stability of perforation cavities under anticipated production condition was investigated with a FEM numerical model. Based on the sensitivity of the operational conditions, the results demarcated the reservoir rock conditions into "safe", "manageable", and "catastrophic" regions1 with more confidence than before.
This multi-dimensional diagnosis of reservoir rock stability indicated the practical guideline for the well completion through organized logging programs and perforation design (selective/oriented) to minimize the sand risk. It also suggested the general production constraints of critical draw down in the artificial lift to optimize the production operation. Following the introduction of the study in the first chapter, the second chapter summarizes the formation strength characterization. The formation failure analysis using these rock properties is described in the following chapter. The sand control strategies based on this analysis are briefly summarized as concluding remarks.
Case Study: Coalbed Methane Automation System for River Gas Corporation
Authors: Robertson Steve K. , Pool Mike , Farrens Michael J. , Butts Tammie J. 
Published: December 2007

Abstract
Can an independent producer fulfill a vision to develop and produce a coalbed methane gas field that covers two hundred square miles in a remote desert plateau in the western United States? This paper answers that question as well as provides answers to other pertinent questions such as, "What tools would be available to the operator to efficiently and safely produce the wells?" And, "Would the tools allow for future expansion and/or allow state-of-the-art technologies to be cost effectively incorporated into the system?"
This case study shows how River Gas Corporation successfully implemented an automation system that was jointly developed with an engineering/manufacturing company to efficiently fulfill their needs.
All phases of the project from its inception in 1991 with a 13-well pilot project to a planned 600-well development will be discussed along with the innovative methods that were applied to address the above questions. The resulting system was capable of successfully meeting the continuing changes in expansion and production.
Integration of Computer-Aided High-Intensity Design with Reservoir Exploitation of Remote and Offshore Locations
Authors: Saputelli Luigi , Cherian Bilu , Gregoriadis Karolos , Nikolaou Michael , Oudinot Cedric , Reddy Gopal , Economides Michael J. , Ehlig-Economides Christine 
Published: December 2007

Abstract
Offshore and remote-location hydrocarbon production structures operate in a dynamic (unsteady state) environment where decisions continually have to be made about equipment design, construction, and operation. Such decisions and resulting subsequent actions have a significant and lasting effect on the operation, safety, and profitability of the structure. For example, during the life of an offshore structure, decisions have to be made about the number, placement, and design of separators, dehydration, sweetening or other processing units; switching times from production to injection; timing and location of multilateral branches; etc.
The engineer faced with carrying out tasks such as the above may be substantially aided by suitable computer-aideddesign-and-operation software tools. Use of such tools could streamline or automate design tasks (thus improving repeatability and reliability of task completion, making efficient use of manpower, reducing task completion time, effectively coordinating interdependent concurrent tasks, and cost-effectively approaching optimality) andoptimize operating strategies (thus safely and reliably improving long-term profitability without burdening the engineer with excessive decision making tasks).
This paper introduces the technology of integrated computer-aided design and operations to petroleum production. Current practices in other industries such as oil refining, petrochemicals, and aerospace will be investigated with the intention, first, to modify them for petroleum applications and, potentially, advance the state-of-the-art.
Observed Contaminant Migration from an Instrumented Reserve Pit
Authors: Deuel Lloyd E. , Holliday George H. 
Published: December 2007

Abstract
A 3.3-meter deep fresh water drilling fluid reserve pit was instrumented to determine migration of contaminates from the pit during drilling and after pit closure. The ability to predict impacts from earthen drilling pits has become important, due to the recognized potential for an adverse impact on soil and water resources. The results of the field study allow operators to control chemical composition of pit wastes to prevent contaminants from migrating from an active or closed pit. To the best of our knowledge, no other reserve pit has been evaluated by instrumentation installed a priori to evaluate the environmental impact of reserve pits.
The pit was equipped with neutron probe access tubes, barrel size lysimeters, vacuum extraction moisture cups and gypsum resistively blocks at 4 stations within the pit perimeter. Ground water monitoring wells, and post closure soil borings were used to assess the long-term affects of the earthen pit use and onsite disposal of the pit waste solids on soil and ground water resources.
The soil moisture and chemical data generated during the 2-year field study was evaluated statistically utilizing analyses of variance (ANOVA). Soil water monitoring during pit use showed the soil profile below the pit remained unsaturated under the influence of a 3.3-m head of pit fluid. This demonstrated the clay gels [spud mud] serve as a pit surface sealant and retards percolation of fluids from the pit. Chlorides were retained in the pit by an anion exclusion mechanism. This mechanism remained stable and the exclusion volume functional in pit solids having Saturated Paste Electrical Conductivity [SPEC] of ? 24 mmhos/cm. Post closure data show clean closure of the study pit and no alteration of intended land use (improved pasture) or adverse impact to the natural environment.