bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Role of the Local Petroleum Service Company in Asset Management
Authors: Barwani M. , Marhubi A. , Oligney R. E. , Economides M. J. 
Published: December 2007

Abstract
Petroleum production grows from frontier to semi-mature to mature. There have been several attempts to quantify a petroleum region's production profile, including seminal works by Hubbert and others. Both the physics of production and the economics of exploitation are presumed to influence this profile. Defying the log-normal distribution which was suggested by Hubbert, entire petroleum provinces have extended their production history into a much flatter and considerably wider profile, recently characterized as fractal. Maturity implies, among other characteristics, small pool exploration, commoditized drilling and, especially, production enhancement services. We suggest that the transition in the production profile is characterized and at the same time aided by the flight of the major service company (which has become even bigger and more diversified) and its replacement by smaller service companies. There are significant distinctions between the local and international service companies. These include issues such as local vs. global knowledge, non-integrated vs. integrated services and a low vs. high comfort level by the clients. The mix of the local service companies can be greatly affected by the local operators. It must be emphasized that the quality and spectrum of services are crucial elements for the survival of the local petroleum production. We present here a model for the local service company/operator interaction, the changing role of the major service companies and criteria for technology utilization and required proficiency. We apply these concepts to a highly mature area (Oklahoma) and to Oman, entering maturity now.
Single Well Reservoir Management - the Ultimate Multibranch Well Challenge
Authors: Ehlig-Economides C. A. , Economides M. J. 
Published: December 2007

Abstract
Whether due to the lure of deep-water prospects or the shear excitement to apply new technology, the recently developed multibranch wells are likely to play a crucial role in the future of petroleum exploitation. The challenge is to adjust and even develop reservoir management strategies both suited to and taking advantage of this technology. In effect, a multibranch well provides an underground gathering system. When the design includes downhole separation that provides for the production at the surface of desired fluids with reinjection of unwanted ones, the well incorporates an underground production facility. To achieve these sorts of objectives, the entire system of branches, completions, manifolds, separators, etc., must be in place and operational before the well can begin to produce. The design considerations that would enable this result rely on a modular approach to the problem and provision for contingencies for uncertainties in the reservoir description and in the reliability of the underground system. This paper outlines the issues that must be considered and provides a framework for the well design process.
Optimizing Simulation Models by Upscaling from Integrated Reservoirs Models: A Case History
Authors: Ali Zaki A. , Al-Qassab Hisham M. 
Published: December 2007

Abstract
This paper presents a case study of using integrated models in improving upscale accuracy that increases the model speed. This has a great impact on CPU time and therefore the cost of the study. A unique process that integrates data from all possible sources (open hole logs, RFT and production data, seismic and geologic interpretations) was used in a geologic model. This static geologic model was then used to build a DYNAMIC simulation model. We superimposed water encroachment movement over the geologic model that in turn was recycled back in developing the simulation (engineering) model. Up-scaling the resultant model was done using a multi step technique that captured all the varying details of the complex reservoir such as:
a) A tilt in the free water level coupled with the effect of capillary forces on reservoir fluid distribution; b) Reservoir stratification which has the effect of limiting bottom water support and causing the injected water to move rapidly through the high permeability layers; c) While the effects of stratification and faulting are apparent, communication is observed across these features.The study was done on a sector model extracted from the full field geological model as a pilot testing of the method. The same procedure was then applied to the full field model. As a result of using this technique, pressure and water saturation match was obtained and prediction cases were submitted to predict reservoir performance for designing operational and production strategies for the field.
History Match of the Complex Carbonate Neelam Field
Authors: Carnegie A , Joshi S , Lahiri G 
Published: December 2007

Abstract
Neelam is a heterogeneous carbonate oil field, located offshore India. In addition to aquifer and gas drives, pressure is maintained by water injection. Production is from vertical, deviated and horizontal wells. Severe, unexpected production problems, such as high water cuts and low oil rates, have been encountered. To address these, a multi-disciplinary reservoir study was performed, which integrated available data, and has created a history matched flow simulation model of the field. This model will aid development of strategies to optimise the oil recovery from the field. The characterisation of the field to prepare it for flow simulation was described in another SPE paper (1). There it was shown how diverse types of information, for example well logs and acoustic impedance's derived from seismic data, were integrated using advanced techniques and software to efficiently create an input model for flow simulation. This paper describes the history matching of that model with a fluid flow simulator. It will show that for much of the field, the model actually did not require much modification, thereby validating the approach described in the previous paper. This is noteworthy, given that flow properties of carbonate fields (including Neelam) can be potentially very difficult to capture. However, as will be described, during the history match the model did need development in certain crucial areas. Notably, the areal compartmentalization of the field into separate flow blocks after a major material balance study, and the implementation of high permeability streaks, which were inferred from dynamic data (production logs, production rates and pressures, RFT's). It will be explained that the identification and parametrisation of such streaks was aided by a simple probabilistic technique implemented in an interactive PC package developed by the team during the project. Finally, descriptions will be provided of the strategies, which were developed to efficiently achieve a realistic history match in spite of the difficult nature of the problem. These strategies will be used to suggest some general recommendations on workflow and procedures in integrated reservoir studies.
The Application of Probabilistic and Qualitative Methods to Asset Management Decision Making
Authors: Simpson G. S. , Lamb F. E. , Finch J. H. , Dinnie N. C. 
Published: December 2007

Abstract
Interviews have been conducted with decision-makers in most of the operating companies active in the UK North Sea. The data generated by these interviews defines industry current capability in decision analysis. The extent to which each company uses the techniques which comprise current capability defines a rank list representing relative level of sophistication in decision analysis. This rank list is then correlated with other rank lists based on common measures of business performance to establish the value, to companies, of adopting best (or, at least, better) practice in decision analysis. The strong positive correlation found indicates a considerable incentive for companies to upgrade their decision analysis capability.
Asset Optimization Using Multiple Realizations and Streamline Simulation
Authors: Pallister I. C. , Ponting D. K. 
Published: December 2007

Abstract
Reservoir simulation results may be presented in terms of asset net present value. This may be used to make decisions regarding alternative production strategies or in-fill drilling programs based upon economic criteria. If the simulation and value assessment is performed for a number of possible realizations of the reservoir geological model an estimate is also obtained of the risk involved in each production decision made. Ideally, optimal strategies for all realizations should be compared, rather than one tuned to a single possibility.
Such a system implies a fast reservoir flow simulation engine. One possibility is to use a streamline solver. These yield simulation results quickly, but introduce significant approximations in the treatment of gravity and viscosity changes. An alternative is to use a fast finite difference or finite element simulator. We compare the results obtained using these methods, in economic terms as well as in terms of production profiles.
Full Field Model Study of a Dense Highly Fractured Carbonate Reservoir
Authors: Fathi A. , Ansari A. 
Published: December 2007

Abstract
The purpose of this paper is to present the results of a comprehensive subsurface study of a field in South of Iran. The reservoir is typical of several carbonate fields in south west Iran, comprising low porosity carbonate, but highly fractured. After several years of natural depletion a gas injection was started at a time that reservoir became saturated at the crest to prevent further shrinkage of the oil and keep the reservoir oil pressure constant. The source of gas was a deeper reservoir where the gas was produced and injected by its own pressure through one producer and one injector.
A three dimensional model was set up using a 3D static model as the basis for geological input. All available data including, fluid losses during drilling, well test and flowmeter surveys were used to define the fracture properties. A good history match was obtained for pressure and fluid levels with a commercial black oil simulator using the model in dual porosity mode. The calibrated model was then used in prediction mode to forecast the reservoir behavior under gas injection pressure maintenance and also repressuring close to original crestal pressure. The simulation results show large increase in ultimate recovery due to gas injection as compared with natural depletion.
Three Dimensional Seismic Survey in Ogata, Japan
Authors: Minegishi M. , Aoki N. , Higashinaka M. , Tamura Y. , Amano H. 
Published: December 2007

Abstract
A 3D seismic survey was conducted in Ogata area, one of Japanese mature oil fields. The survey was aimed to obtain a basic data set, which is useful for studying the effects of irregular data acquisition geometry, and to provide the precise information on the subsurface structure for finding additional reserves. The survey area was previously the second largest lake in Japan and has been changed to rice fields after reclamation. Few difficulties in seismic data acquisition were expected and dense regular data acquisition geometry was planned to use in the survey. However, acquisition work encountered many hazards because a lot of unexpected constraints came from the reclaimed land. Moreover, obtained shot records showed the very complex nature of seismic wave fields. Especially, strong ringing waves masked weak reflection signals. Spatial variation of these ringing waves was investigated and the origin was modeled as critical refraction of multiple reflected waves within a very thin surface layer. Those results can provide valuable knowledge for seismic survey in areas with similar surface conditions. In seismic data processing, these ringing waves were successfully suppressed at the earlier data processing stage by FK filter in common shot and receiver domains followed by deconvolution. After this suppression, remaining data processing became more effective and gave a precise depth image. Various analyses to the obtained processing vintage such as coherency cube and attributes revealed the existence of minor faults precisely, which were not recognized previously. These could give a new interpretation of the area. As a result, the data set can be very useful for the evaluation of irregular data acquisition geometry as well as the exploration in the area.
Casing Failure In Steam Stimulated Wells A Case History Of The Guapo Field
Authors: Bissoondatt J.C. 
Published: December 2007

Abstract
Casing failure in production wells stimulated with steam presents economic and technical limitations in the application of the method. Completion of a steam injection well must be designed so that saturated steam can be injected into an oil reservoir at the desired rate, pressure or temperature and heat content. During the injection of steam, heat is lost to the surrounding well bore, equipment and the earth due to the high temperature of the steam. It is therefore desirable to design the completion so that heat loss is minimised and the casing temperature is kept low enough to prevent casing damage whilst ensuring that most of the steam goes into the productive formation. productive formation

Introduction
The Upper Cruse sands of the Guapo Field have been under thermal exploitation, 'Huffing n Puffing', since August 1968 when a pilot project was initiated using a portable steam generator. Early results from the pilot indicated that economic production could be obtained from these viscous (1600 cp at 100 deg. F) oil reservoirs as production rates were increased from 15 bopd up to 100 bopd and in some cases up to 200 bopd.
As a result of the successful pilot a major expansion programme was vigorously embarked upon. Over 100 programme was vigorously embarked upon. Over 100 wells were drilled from the period mid 1971 to present and fixed generators installed.
After 3 years of 'huffing n puffing' it was found that many of the wells had parted casing and damaged gravel pack liners. To date, 15 casing and 50 gravel packed liner failures have been positively identified. packed liner failures have been positively identified. The text that follows outlines some of the procedures adopted and problems encountered procedures adopted and problems encountered and suggests principles that should be taken into account when designing steam injection - production wells of this nature.
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Distinguishing Between Oil and Gas in Shaly Sands - A Case History
Authors: Alleyne N.A.B. , Harper W.N. 
Published: December 2007

Abstract
A primary logging technique used for distinguishing between oil and gas in reservoirs is the overlaying of the Compensated Neutron Log (CNL) Compensated Formation Density (FDC) Log. Whereas this technique is very reliable in clean sands, in shaly sands, however, the log must be corrected for the effects of shale. Methods of correcting the CNL and FDC logs for the effects of shale have been devised, but though these methods are very reliable, they are neither suitable for use at the well site nor for use in quickly distinguishing between oil and gas. Amoco Trinidad Oil Company (ATOC) adopted a method for correcting for the effects of shale on the CNL and FDC Logs called V SHALE ANALYSIS. This method is a modification of a more sophisticated analysis and field tests have proven it to be reliable. The method is suitable for use at the well site for the quick differentiation between oil and gas bearing zones.

Introduction
Many of the reservoirs in the oil fields of Trinidad, West Indies (Fig. 1)occur in sandstone formations which contain varying quantities of shale. In this respect, the reservoirs in the oilfields off the East Coast of Trinidad which are being operated by ATOC are no exceptions. Since commencing operations, ATOC has developed three oil fields, the Teak Field, the Samaan Field, and the Poui Field. Of these, the Teak Field, which is infamous for its sand production problems, was the first to be developed. Generally, the reservoirs in the Teak Field were relatively clean sands and, as a result, overlaying the Compensated Neutron Log (CNL) with the Formation Density Log(FDC) gave very clear and reliable distinction between oil and gas zones. The Samaan Field was discovered after the Teak Field and it differed from the Teak Field in that its sands were generally shalier. The shaly nature of the sands in the Samaan Field had an adverse effect on the technique of overlaying the CNL and FDC Logs to distinguish between oil and gas bearing zones. The need therefore arose for a method of correcting the CNL and FDC Logs for the effects of shale. Methods were available which gave adequate correction for the effects of shale on these logs, but they were unsuitable for the quick determination of hydrocarbon contents at the well site, since they either required tedious hand calculations or utilized a computer. ATOC therefore adopted a method called VSHALE ANALYSIS to correct for the effects of shale on CNL and FDC Logs. V-Shaleanalysis is a modification of a more sophisticated computer method called SARABAND 1.
This paper summarizes the procedure of the V-Shale Analysis and also describes the result which ATOC has had with it.
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A Coiled Tubing-Deployed Slow-Rotating Jet Cleaning Tool Enhances Cleaning and Allows Jet Cutting of Tubulars
Authors: Connell Mike , Courville Perry , Tucker James 
Published: December 2007

Abstract
Tubular restrictions from scale buildup can significantly reduce hydrocarbon production, and buildup must be removed to restore the production capacity of a well. Although scale buildup is a global problem, the material composition and characteristics of scales can vary drastically, even within the same field, making most tools on location insufficient for scale removal. A customized jet cleaning tool has recently been developed to address the problems associated with tubular cleaning operations.
Traditional jet cleaning tools are insufficient for removing scale buildup because they do not reliably control jet dwell time. Jet dwell time is the relationship between the difficulty of tubular cleaning and the time required for scale removal. Jet dwell time increases with an increase in the hardness of the buildup material. Ability to control dwell time is a measure of cleaning efficiency. A new, slow-rotating jet cleaning tool can help optimize jet dwell time for cleaning operations without repetitive cyclic effects on a coiled tubing (CT) workstring.
The slow-rotating jet cleaning tool can also be used for cutting tubulars. Previously, tubulars were cut by mechanical, explosive, or chemical methods, and CT was used to deploy positive-displacement motors (PDM's) and pressure-activated firing devices (used for rotating the mechanical cutters and initiating the firing sequence in explosive or chemical cutters, respectively). For many through-tubing applications, traditional cutting methods created significant safety risks and obstacles such as long bottomhole assemblies, increasing service costs. With its capability to control jet dwell time and pump abrasive fluids, the new jet cleaning tool can reduce the safety risks and the costs associated with traditional cutting methods.
This paper discusses the design and application of the slow-rotating jet cutting tool, and provides case histories of the tool's use in removing scale and production buildup on tubing walls. The paper also discusses application of the tool for performing through-tubing cuts.
Predicting Core Porosity using Wire-Line Logs at Dagger Draw Field, SE New Mexico
Authors: Balch R. S. , Weiss W. W. , Wo S. , Welch D. 
Published: December 2007

Abstract
At Dagger Draw it is difficult to arrive at reliable estimates of total pore volume in the vuggy dolomitic reservoir. Correlating wire-line logs to core porosity using a multi-layer perceptron neural network (MLP) generated a "ground truth" porosity estimator for the reservoir. Well logs in the field include CAL, DRHO, GR, LLD, LLS, MSFL, NPHI, PEF, RHOB, and values of DPHI, PHI-L (liquid phase porosity) and PHI-G (gas phase porosity) were calculated. Log values were aligned with the center point of laboratory analyzed core samples in five cored wells with a total of 21 cored sections. Neural network solutions generated using four of the five wells to blindly predict the fifth well validated results. Each well was excluded in this fashion, for a total of five tests.
The resulting correlation tool, if applied at hundreds of wells within the field without core data, would provide the basis for geostatistically derived pore volume maps.
Fuzzy ranking was used to evaluate the usefulness of individual logs for correlating with core porosity, and also indicated that the problem was complex, and guided architecture design for the MLP. The seven best logs were used as inputs for the MLP, and results show that the MLP can describe the complex relationships between the wire-line data and core porosity. Regression relationship were able to predict the excluded wells at up to CC=0.80. These results are a great improvement on the linear equations previously used for estimating porosity at the Dagger Draw and better predictions are expected, as the process is refined and neural network algorithms are improved.
The use of artificial intelligence to generate core porosity data using only wire-line log data can provide data that could only be attained previously using expensive cores.
Integrated Identification of Possible Compartmented Gas Reservoirs: A Case Study
Authors: Shenawi Shamsuddin H. , Howard William E. , Rowland Bret , Lara Alejandro L. , Zacarias Moises C. , Chavez Gustavo M. 
Published: December 2007

Abstract
This paper presents a method to identify and calculate hydraulically connected gas reserves in compartmented gas reservoirs. The 3-D seismic amplitude analyses and edge detection indicate the possible compartmented sands in the same geological flow units identified in this study. Petrophysical properties of adjacent wells also change abruptly that indicate the deltaic nature of sand deposition in Frio Marine and Frio Non-Marine formations.
The "material balance" method to calculate original gas in place (OGIP) and remaining gas reserves utilizes a plot of p/Z values versus cumulative gas production. The assumption is that all wells should drain from the hydraulically connected tank-type gas sand body. The isolation of wells draining from different sand bodies is important to determine the correct OGIP for each sand body. Therefore, measured shut-in reservoir pressures were plotted against time for each geological flow unit. Plotted pressure profiles for each well made it possible to identify wells draining from a common sand body. Wells draining from a single gas pool had a uniform pressure decline. However, the well that produced from a different gas pool had a distinct pressure decline trend. Several wells encountered initial reservoir pressures even though the corresponding formation that was completed in was put on production 20 years ago.
This paper provides three examples of integrating 3-D seismic amplitudes, production bubble maps and pressure analyses to differentiate hydraulically connected sand bodies. The material balance calculations provide accurate OGIP and remaining gas reserves. This method identifies significant volumes of remaining gas reserves that lead to reopening of shut in gas wells utilizing minor workovers.