bluuebunny/crossref_metadata_2025_split huggingface dataset:
Operational Procedures and Applications of a Wireline Formation Tester to Accurately Characterise the Gas Composition of Stacked Multiple Pools in the North Malay Basin
Authors: Baxter Martin F. W. , Abdullah Zulkiflie , Pearson Michael R. 
Published: December 2007

Abstract
An accurate knowledge of reservoir fluid composition, specifically the concentration of hydrocarbon gases and non-combustible gases such as carbon dioxide, is a key factor in the commercial assessment of upstream gas projects at the exploration and field appraisal drilling stages, and in development planning.
The precise measurement of reservoir fluid composition requires the acquisition of a representative sample of formation fluid, free of drilling fluids and other contaminants. Traditionally, Drill Stem Tests have offered the most reliable method to obtain this information. However, the cost of this method limits its application in gas accumulations comprised of multiple, stacked, separate pools where the individual reservoir fluid compositions need to be well known.
Carigali Triton Operating Company Sdn. Bhd. (CTOC), Operator of Block A-18, JDA on behalf of its Shareholders, Petronas Carigali (JDA) Sdn. Bhd., Triton Oil Company of Thailand (JDA) Limited and Triton Oil Company of Thailand Inc., is now consistently able to acquire reservoir fluid samples which are confirmed by on-site advanced chromatography, and calibrated by Drill Stem Tests to be fully representative of in-situ native reservoir fluid compositions. This has been achieved through the use of a wireline formation tester with an enhanced pump-out capability and a downhole fluid analyser, together with the development and implementation of key operational procedures for performing the logging operation.
The accuracy and reliability of the technique has been proven and refined over the sixteen-well exploration program in Block A-18, where downhole conditions can be hostile, and tool operating time has exceeded 40 hours. This technique has enabled the Operator to obtain specific and accurate information on the fluid composition of individual reservoirs, and therefore reduce appraisal and development uncertainties, in a fraction of the time which would have been needed for conventional Drill Stem Testing, and at a fraction of the cost.
This paper describes the tool, together with the techniques that have been implemented at the well site to obtain representative reservoir fluid samples in an efficient and cost-effective manner. Wireline Formation Tester Drill Stem Test results from the Block A-18 exploration and appraisal program to date are compared to demonstrate the accuracy and reliability of the methods employed.
A Comprehensive Monograph for Hydraulic Fracture Initiation From Deviated Wellbores Under Arbitrary Stress Regimes
Authors: Hossain M. M. , Rahman M. K. , Rahman Sheik S 
Published: December 2007

Abstract
Hydraulic fracturing is a widely used stimulation technique in the petroleum industry for enhanced hydrocarbon recovery from low permeable reservoirs. Technological advancements in directional drilling have led the petroleum industry to drill arbitrarily deviated wellbores for development of reservoirs, which otherwise could not be economically produced. Efficient prediction of fracture initiation pressure from such deviated wellbores is therefore essential for petroleum industries to undertake effective hydraulic fracture stimulation tasks. This paper presents a generic model for prediction of hydraulic fracture initiation pressure and the orientation and location of fractures on the wellbore wall. The generic model is finally ramified to develop criteria for initiation of longitudinal, transverse and T-shaped or H-shaped fractures, with and without perforations. Final form of fracture initiation criteria for specified cases presented in the paper can be used by engineers for prediction of fracture initiation pressure. However, the estimation of fracture initiation pressure for deviated wellbores is cumbersome requiring numerical iterations. For such cases, results are presented graphically in terms of non-dimensional parameters to cover various stress regimes and wellbore deviations. Thus, the charts presented in this paper will be a useful tool for prediction of fracture initiation pressure for given in-situ stresses and help engineers to minimize computational efforts.
Results of this study suggest that horizontal wellbores under the normal faulting stress condition requires less pressure for fracture initiation compared to vertical wellbores. In general, there is an optimum deviation that requires minimum fracture initiation pressure for a given set of in-situ stresses. Longitudinal fractures usually initiate from wellbores which are aligned with one of the in-situ stresses. Under some specific stress conditions, transverse fractures may also initiate directly from the wellbore wall. Without appropriate pressure control, longitudinal fractures also, however, initiate at some elevated pressure during the propagation of transverse fractures. This introduces the so-called T-shaped or H-shaped fractures. Perforations at appropriate alignment usually contribute in fracture initiation at lowe pressure.
A Unique Method of Paraffin Control in Production Operations
Authors: Dobbs James B. 
Published: December 2007

Abstract
Paraffin deposition has long been a problem for many oil producing areas. The use of paraffin inhibitors, which are sometimes referred to as wax crystal modifiers or pour point depressants, have been effective at reducing problems caused by paraffin deposition. These materials must be applied at a point before the paraffin falls out of solution and they must be present on a continuous basis. This presentation describes a technique for squeezing inhibitor into the reservoir rock matrix to get a slow consist return of inhibitor that provides an extended treatment for controlling deposition.
The Experimental Studies of Physical Simulation of Bottom Water Reservoirs With Barrier and Permeable Interbed on Horizontal Well
Authors: Dou Hongen , Guan Changzhi , Lian Shengjiang 
Published: December 2007

Abstract
The paper presents the experimental study that is flow mechanism of bottom water breakthrough into oil well with horizontal well of barrier interbed and permeable interbed was studied, and reservoir physical simulations of barrier layer and permeable interbed flow of horizontal well were performed by 2D physical visible model. The model is made of two polymethylmethacrylucote planes of transparent and the metal frame that dimensional is 700mm × 300mm × 14mm. The production mechanism and flow behavior of bottom water reservoirs of barrier interbed and permeable interbed horizontal well was revealed. All development process of water cresting of barrier interbed and permeable interbed were shown by the experiment. Meanwhile, the some rules that are point displacement no better than the displacement of bottom water, and there is no phenomenal of water cresting to the permeable interbed, and result in water-free recovery percent of reserves and terminal oil recovery both are enhancement. The authors discovered that the weak permeable interbed had high water-free recovery percentage of reserves and terminal oil recovery after the weak permeable interbed compares with the barrier interbed. The experiment reveals the to effect horizontal well production rate on main sensitive factors, such as the horizontal well length and the displacement pressure drawdown. The paper presents also same horizontal well length to increase pressure drawdown about two times then terminal oil recovery to decline 3.14per cent and water-free recovery percentage of reserves to decline 13.7per cent to the weak permeable interbed. The bottom water reservoir of weak permeable interbed and barrier interbed both should develop to mitigate water cresting and prolong bottom water breakthrough into oil well in the some degrees respectively.
Using the multilateral well to build up manual barrier layer for the water control in bottom water reservoir with horizontal well. The new concept development has been established through the experiment.
Oil Recovery Potential From Fractured Reservoirs by Mass Transfer Processes
Authors: Stubos A. K. , Poulou S. 
Published: December 2007

Abstract
The purpose of this work is to evaluate the incremental oil recovery by evaporation and diffusion processes in fractured reservoirs and to provide a simple method for scale-up assessments. A macroscopic analysis of the flow and mass transfer phenomena in the porous matrix is performed on the basis of previously published experimental observations on core samples. This leads to analytical expressions for the evaporation, or, equivalently, drying rate, the extent of the two-phase zone in the matrix, and the location of the propagating front during both the steady and the falling rate periods of the process. Such expressions permit fast, albeit approximate, scaling considerations and recovery potential calculations. They also lead to conclusions concerning the optimal injection conditions and the desired injection gas properties.
Processing and Interpretation of Long-term Data from Permanent Downhole Pressure Gauges
Authors: Athichanagorn Suwat , Horne Roland N. , Kikani Jitendra 
Published: December 2007

Abstract
Long-term data from permanent gauges have the potential to provide more information about a reservoir than data from traditional pressure transient tests that last for a relatively small duration. Besides reducing ambiguity and uncertainties in the interpretation, long-term data also provide an insight on how reservoir properties may change as the reservoir is produced. This type of long-term surveillance provides the opportunity to look at the reservoir information in four dimensions rather than obtaining a glimpse or snapshot in time. However, the installation of permanent downhole gauges is only a recent phenomenon, and a methodology for the interpretation of the data has yet to be developed. The use of long-term data requires special handling and interpretation techniques due to the instability of in-situ permanent data acquisition systems, extremely large volume of data, incomplete flow rate history caused by unmeasured and uncertain rate changes, and dynamic changes in reservoir conditions and properties throughout the life of the reservoir.
This study developed a multistep procedure for the processing and interpretation of long-term pressure data. The procedure was tested with several sets of simulated and actual field data. It was found to be an effective approach for the analysis of long-term pressure data from permanent gauges.
Determining Depth-Dependent Reservoir Properties Using Integrated Data Analysis
Authors: Phan Vinh , Horne Roland N. 
Published: December 2007

Abstract
The ambition of modern reservoir modeling is to make integrated use of dynamic data from multiple sources to infer the reservoir properties. The process of inferring the reservoir properties from indirect measurement is an inverse or parameter estimation problem.
The parameters of interest in this work are porosity and absolute permeability. These parameters have important influence in determining the performance of the reservoir and in reservoir optimization. This work represents a way of estimating such parameters from a variety of indirect measurements such as well test data, long-term pressure and water-oil ratio history, and 4-D seismic information. The work also considers the effect of the data on the uncertainty and resolution of reservoir parameters. In particular, since earlier work has addressed two-dimensional problems, this study focuses on the estimation of parameters in three dimensions where properties vary as a function of depth.
The study determined that depth-dependent properties can be estimated to varying degrees of precision, depending on the resolution of the data used to constrain the model. Seismic data generally has poor depth resolution, hence it was found that parameter estimates are better determined areally.
Use of Experimental and Simulation Results for Estimating Critical and Optimum Water Injection Rates in Naturally Fractured Reservoirs
Authors: Putra E. , Fidra Y. , Schlechter D. S. 
Published: December 2007

Abstract
This paper describes the experimental and simulation studies to determine critical and optimum injection rates during waterflooding in the naturally fractured reservoirs of the Spraberry Trend Area. The experimental study was performed using artificially fractured cores at reservoir temperature (138°F) and 500 psia confining pressure.
Based on the experimental results, an equation to determine the critical water injection rate (maximum injection rate at which the capillary imbibition is not effective) was developed to scale up laboratory results to field dimensions. We found that capillary imbibition transfer is not only a function of matrix permeability and maximum matrix capillary pressure but also a function of other matrix properties, such as wettability, porosity, matrix area and water viscosity. Two field cases using this scale-up equation are presented.
The optimum injection rate (the injection rate at which the capillary imbibition and viscous forces are balanced) for different well configurations cannot be determined from laboratory experiments; therefore, a reservoir simulation was employed. A 40-acre pilot was developed by utilizing a commercial dual-porosity simulator. Three different injection schemes were applied for four vertical and two horizontal injection wells, with constant injection rate and two different cyclic injection rate schemes. The numerical results show that four vertical injection wells at the optimum injection rate could yield higher oil production than two horizontal injection wells at the optimum injection rate. Use of a cyclic injection rate could restore reservoir pressure and increase oil recovery in the Spraberry Trend Area. The findings of this study could be useful to solve the problem of early water breakthrough, one of common problems of waterflooding in all naturally fractured reservoirs.
Development of a New Fiber-Optic-Based Offshore Structural Monitoring System
Authors: Guaita Paolo 
Published: December 2007

Abstract
The paper focuses on a new structural monitoring system based on the use of fiber optic strain sensors. This system has been developed and tested at sea on a full scale experimental riser in the frame of an R&D project fully funded by ENI/Agip division. The system is based on the measurement of longitudinal deformation of optical fibers via interferometric techniques. No active device is located underwater while all the system's complexity is grouped and packaged in a conventional electronic rack.
The test at sea of such a system is, to our knowledge, a world first not only for the oil industry.
The activities that led to the development and full scale test of the new Fiber optic based system (research objectives, Feasibility study, laboratory experiments, full scale test description, test results) are described.
Description of the main features of the new system and comparison with conventional electronic systems is provided
Application of Neural Networks for Predictive Control in Drilling Dynamics
Authors: Dashevskiy D. , Dubinsky V. , Macpherson J. D. 
Published: December 2007

Abstract
Real-time monitoring of BHA and drill bit dynamic behavior is a critical factor in improving drilling efficiency. It allows the driller to avoid detrimental drillstring vibrations and maintain optimum drilling conditions through periodic adjustments to various surface control parameters (such as hook load, RPM, flow rate and mud properties). However, selection of the correct control parameters is not a trivial task. A few iterations in parameter modification may be required before the desired effect is achieved and, even then, the result may not be optimal. For this reason, the development of efficient methods to predict the dynamic behavior of the BHA, and methods to select the appropriate control parameters, is important for drilling optimization.
The approach presented in this paper uses the power of Neural Networks (NN) to model the dynamic behavior of the non-linear, multi- input/output drilling system. Such a model, along with an optimizing controller, provides the driller with a quantified recommendation on the appropriate corrective action(s) required to bring the system to an optimal drilling condition.
Development of the NN model used drilling dynamics data from a field test. This field test involved various drilling scenarios in different lithologic units. The training and fine-tuning of the basic model utilized both surface and downhole dynamics data recorded in real-time while drilling. Measurement of the dynamic state of the BHA was achieved using data from downhole vibration sensors. This information, which represents the effects of modifying the surface control parameters, was recorded in the memory of the downhole tool. Representative portions of this test data set, along with the corresponding set of input-output control parameters, were used in developing and training the model.
Test results are promising: There is good agreement between the dynamic behavior of the BHA predicted by the NN model and the actual measured BHA response. In addition, the test established criteria for selecting the most important input-output parameters and for selecting representative data sets for building and training the model.
This analysis has demonstrated a promising approach to simulation and prediction of the dynamic behavior of the complex multi-parameter drilling system. This method could become a powerful alternative to traditional analytic or direct numerical modeling and its utilization could be extended beyond drilling dynamics to the field of drilling control and optimization.
Horizon Modeling Using a Three-Dimensional Fault Restoration Technique
Authors: Hoffman Karen S. , Neave John W. 
Published: December 2007

Abstract
Rigorous, internally consistent three-dimensional subsurface models are extremely useful in interpretation, mapping, well planning, and simulation pre-processing. The geospatial technique to create these models has been in use for several years, and complicated, highly faulted structures (including overthrusts and other multi-valued surfaces) have been modeled quite successfully. Often, however, the gridding process used to create the horizon surfaces required additional control points, and the shape of the overall structure was not necessarily continued from one fault block to another. A new algorithm has now been developed that uses a three-dimensional model of the faulting process itself to restore data to a pre-faulted condition. Displacement on a given fault surface can vary laterally as well as in depth, and faults which terminate within the model volume are of course accommodated. All horizons are used simultaneously in the process of creating the fault displacement model, which eliminates problems with sparse control or narrow fault blocks. The structural surfaces are then calculated in unfaulted space, and the faulting model is used to transform the resulting surfaces back to the proper structural position. Not only is this algorithm significantly faster, but it also mimics the post-depositional faulting process and produces a geologically consistent model. This consistency and integrity mean that greater confidence can be placed in the model, improving volume calculations and allowing placement of wells with greater precision. The reduced cycle time allows a greater range of scenarios to be modeled and evaluated, thus enabling better risk assessment in complexly faulted fields.
How Could You Possibly Predict the Value of 3-D Seismic Before You Shoot It?
Authors: Head Kim J. 
Published: December 2007

Abstract
It is relatively easy to estimate the cost of acquiring, processing and interpreting 3-D seismic data, but what about predicting its value? Some prediction is needed in order to make a business case for acquiring the additional data.
The Value of Information (VOI) can be estimated by combining a number of financial and statistical analytical methods. The VOI will ultimately depend on two key components: the possible impact on the amounts and timing of expenditures and revenues, and on the resulting Net Present Value (NPV) of the anticipated cash flow stream; andthe possible impact on the Probability of Scientific Success (Ps).
Published historical information from several companies shows that 3-D data has reduced structural uncertainty, increased reserves by identifying by-passed pay zones, improved drilling success rates, reduced the number of development wells required through optimum well positioning, led to faster development programs and faster pay-out, and terminated numerous prospects. The impact of these effects can be estimated based on industry experience.
This leads to evaluating how the additional data might impact the drilling and capital expenditure program. This could range anywhere from condemning the prospect to drilling a significantly larger number of wells and building proportionately larger gathering and processing facilities, which in turn could delay revenues and expenditures. When the realm of possibility is understood, the potential effect on the Net Present Value of the anticipated cash flow stream can be estimated.
Understanding the potential impact on the cash flow stream makes it possible to determine the Expected Value of Perfect Information (EVPI). Since no information is perfect, the EVPI will represent an upper limit on the VOI. Residual uncertainty will determine the actual value of the additional information.
This leaves the possible effect on the Probability of Scientific Success. There are a number of methods for estimating this effect including Delphi methods, Monte Carlo simulation, and using published industry data. Regardless of which method is used, internal consistency will be critical to producing a reliable estimate.
Once the possible effects on NPV and on the Probability of Scientific Success are known, the Value of Information can be predicted using a Decision Tree method. It then remains to compare the value of information with the cost to determine whether to proceed.