bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimating Formation Properties in Heterogeneous Reservoirs Using 3D Interval Pressure Transient Test and Geostatistical Data
Authors: Gok I. M. , Onur M. , Kuchuk F. J. 
Published: December 2007

Proposal
The medium scale formation heterogeneity (about 1 foot to 100 feet near-wellbore) cannot be usually resolved well by conventional well test data, particularly in vertical direction. Spatial pressure data sets from the interval pressure transient testing (IPTT) along the wellbore measured by using multi-probe and dual packer-probe wireline formation testers (WFT) provide information about near-wellbore heterogeneity. The objective of this work is to examine the use of spatial 3D (three dimensional) IPTT data acquired by dual packer-probe WFTs and geostatistical information for estimating heterogeneous formation properties (e.g. horizontal and vertical permeability) in both lateral and vertical directions along the wellbore. There has been no systematic study in the literature about resolving heterogeneity in horizontal and vertical permeability and porosity from spatial 3D IPTT data. Throughout, formation property and parameter will be used interchangeably.
In this study, a 3D single-phase single-well (r-T-z) numerical flow model (simulator) was developed to simulate the behavior of IPTT measurements in heterogeneous media. Heterogeneity in formation properties is modeled at the gridblock scale by using geostatistics that allows properties to be treated as random regional variables with certain correlation structures. Horizontal and vertical property distributions conditional to IPTT data sets are estimated by using the inverse problem methodology based on Bayesian probability theorem. For estimation of formation parameters (properties) conditional to IPTT spatial data sets and geostatistical model, we minimize the objective function resulting from the application of the Bayesian probability theorem by using the well-known Levenberg-Marquardt (LM) algorithm. The sensitivity coefficients required in the LM algorithm are efficiently computed by using the adjoint method. We also show maps of sensitivity coefficients of packer interval and observation probe pressures with respect to parameter distributions (e.g., horizontal/vertical permeabilities and porosities) that offer important evidence about near-wellbore heterogeneities, where formation property distributions might be well resolved by interval pressure transient data.Synthetic examples are presented to show the methodology proposed in this work.
Visualization of Gravity Drainage in a Fractured System During Gas Injection Using Glass Micromodel
Authors: Dastyari A. , Bashukooh B. , Shariatpanahi S. F. , Haghighi M. , Sahimi M. 
Published: December 2007

Abstract
A main mechanism of oil production in naturally-fractured reservoirs is gravity drainage in the gas-invaded zone, where the pressure is below the saturation pressure and the matrix blocks are surrounded by the gas in the fractures. We investigated immiscible gas injection in a single-matrix block using a 2D glass-etched micromodel under the influence of gravity. Two different micromodels containing distinct patterns of the matrix-fracture system were constructed. The fractures were either parallel to the macroscopic flow or perpendicular to it. Extensive experiments on two-phase flow of oil and gas through the micromodels were carried out over a range of the capillary and Bond numbers. The displacement patterns were recorded by a camcorder equipped with a microscope. The images were then processed with an image processing software in order to estimate the initial and residual saturations of the two phases in each experiment. To study the effect of the fractures, we also performed the experiments in the same micromodels but without the fractures.
Our experiments indicate that the residual oil saturation is minimum in the case of natural depletion without gas injection, if the macroscopic flow is aligned with the gravity. However, when the system is inclined at 45 degree (relative to the direction of gravity), or when gas is injected into the system at different angles with respect to the direction of the gravity, the residual oil saturation is more than twice that of the natural depletion. The behavior of the displacement by gravity drainage of oil during gas injection is between two extreme limits of displacements. One is invasion percolation with trapping in which fractal displacement patterns develop, and significant trapping of the displaced fluid takes place. The other limit is similar to diffusion-limited aggregation in which there is no trapping at all, and the displacement pattern is a branched structure.
The Fracture Network Model of Shen 229 Block Buried Hill: A Case Study From the Liaohe Basin, China
Authors: Yuzhong X. , Jichang Z. , Tailiang F. , Zhong C. , Chunming J. , Lihui Z. 
Published: December 2007

Abstract
High oil production from the Proterozoic Formation of Shen 229 block in Da mingtun depression, Liaohe basin, China, indicate the presence of naturally fractured reservoirs whose reservoir's production potential is dominated by the structural fracture. A consistent structural model and a good knowledge of the fracture systems is therefore of key importance in reducing risk in the development strategies. So data from core and image logs have been collected to account for the basic characteristics of fracture, and then the analysis results were integrated with the structural model in order to restrict the fracture network development during the structural evolvement.
The structural evolution of the Proterozoic reservoir through time forms the basis for understanding the development of the 3D fracture system. Seismic interpretation and formation correlation were used to build a 3D geological model. The fault blocks that compose the Proterozoic formation reservoir were subsequently restored to their pre-deformation states using 3D structural modeling software. From here, the structures were kinematically forward modeled to simulate the structural evolution of the reservoirs.
At each time step the dilatational and cumulative strain was calculated throughout the modeling history. The total strain record the total spatial variation in the reservoir due to its structural history, together with core data, well data and the lithology distribution, were used to simulate geologically realistic discrete fracture networks. The benefit of this technique over traditional curvature analysis is that the structural evolution is taken into account, a factor that mostly dominates fracture formation.
HAZOP Studies for Grass-Root Field Development Project
Authors: Saadawi H. 
Published: December 2007

Abstract
The North East Bab (NEB) Project is currently under construction by Abu Dhabi Company for Onshore Oil Operations (ADCO). It is a grass root field development project. New production facilities are installed to handle oil, gas and water production from three separate oil fields; Al Dabbiya, Rumaitha and Shanayel.
In accordance with the project HSE plan, a HAZID (Hazard Identification) study was conducted during the conceptual design phase.HAZOP studies were carried out during the FEED and EPC phases of the project.
This paper describes the role of HAZOP in a complex major project involving full field development.Topics covered include: project description, project HSE plan, HAZOP logistics, main HAZOP findings, follow-up and implementation of the HAZOP recommendations as well as the lessons learnt. Finally, the paper concludes by making recommendations on the effective way to implement HAZOP studies for new projects in an E& P environment.
An Effective Approach for Successfully Drilling Into the Naturally Fractured Reservoir (NFR): A Field Application Study
Authors: Hou X. , Liu G. , Hao L. , Tian A. , Liu Y. 
Published: December 2007

Abstract
Naturally Fractured Reservoir (NFR) characterization represents an increased focus for oil and gas companies as it becomes more and more admitted that they represent a substantial part of their portfolio 1. However the complexity of successfully drilling through fractured reservoirs pushed several service and integrated companies to tackle the fractured reservoir drilling challenge. Moreover the use of effective approaches with the help of UBD and new air technologies are started to show successful results. Tabnak Structure has developmental formation fissure and solution hole, low pressure coefficient, and good connectivity. Therefore, for the low pressure fractured carbonate rocks formation and tight hole of clay shale of Laffan and Kazhdumi formation, it is easy to cause severe circulation loss, serious formation collapsing and frequent pipe sticking. Air drilling and air/foam drilling technology are adopted for the practice operations of Tabnak Structure, which high circulation rates effectively resolved the excellent hole cleaning and avoided the most severe lost circulation zone in 36", 26" and 17 1/2" large hole intervals.
This paper presents the drilling application of coping with large interval of salt and anhydrite. We first cover the drilling difficulty and challenges of designing and operating a large hole into lost circulation formation which has so far proved difficult to drill with conventional drilling method. We then look at the application of air/foam drilling to resolving the lost circulation and hole cleaning problems, and at the same time point to valuable lessons learned from failures.
A Comparative Analysis of Waterflooding Projects using Horizontal Wells
Authors: Algharaib M. , Gharbi R. B. C. 
Published: December 2007

Abstract
The use of horizontal and multilateral wells in oil industry has increased rapidly during the last two decades.The main reason for this upsurge is that horizontal and multilateral wells provide large contact area with the reservoir, and therefore enhance the well productivity or injectivity better than conventional vertical wells.The high productivity coupled with the recent advances in drilling technology for horizontal and multilateral wells has made their application to be an economically viable option.
In this study, the performance of non-conventional wells in water flooding projects was investigated using numerical simulation techniques.Extensive three-dimensional, fine-mesh simulation runs are performed to determine the oil recovery by non-conventional wells under different operating/reservoir conditions.Results show that the pattern used has a significant effect on the displacement performance of non-conventional wells.The study shows the various conditions under which non-conventional wells will perform better than the use of conventional vertical wells
Fracture Flow Property Identification: An Optimized Implementation of Discrete Fracture Network Models
Authors: Basquet R. , Cohen C. E. , Bourbiaux B. 
Published: December 2007

Proposal
The hydraulic characterization of naturally fractured reservoirs is a key point to provide valid flow properties to full-field simulation models. This calibration and validation step is based on the simulation of dynamic data such as flowmeter, transient or interference well tests. Recently, a methodology has been proposed to simulate such tests on Discrete Fracture Network (DFN) models derived from field fracture data integration. However, the drainage area of a well test in a fractured reservoir is generally large, thus leading to numerous computation nodes, especially in the presence of dense fracture networks. In such situations, the CPU time required for a single well test simulation for instance can reveal itself prohibitive.
This paper proposes an original approach to simplify the DFN model in order to reduce drastically the number of fracture nodes, while keeping the same hydraulic properties. This approach keeps the actual fracture network geometry close to the well and replaces the fracture network far from the well by a simplified discrete fracture network. This DFN simplification is performed through an homogenization procedure keeping the same matrix-fracture storativity ratio and interporosity flow parameter. A sensitivity study was carried out to define the area around the wellbore where the fracture network can be simplified. We also defined a connectivity criterium to ensure a representative flow coupling between the actual near-well fracture network and the simplified distant network.
Well tests simulations on this innovative DFN model are compared with simulations on the actual dense fracture network. Then we considered a 3D problem of well testing in a realistic field context. For both cases, the well test signature is not affected by the DFN simplification procedure, but the computation time is reduced drastically, by nearly two orders of magnitude (from 1 hour to 5 minutes CPU for instance). These tests illustrate the major contribution of this new approach. Actually, numerical flow simulation on DFN models can now be carried out at the well drainage area scale and thus be used to tune the field-measured well tests responses: a determinant step to validate the fracture network geometry derived from geological data and to identify fracture conductivities.
How Multi-Component Seismic Can Be Used To Manage Fractured Carbonate Reservoirs
Authors: Kristiansen P. , Gaiser J. , Horne S. 
Published: December 2007

Abstract
Fractured reservoirs have been encountered worldwide and in general they are profitably produced, however it is safe to say that none of them have been depleted efficiently. As the seismic industry focuses more on production and development it is becoming more important to recognize the presence of fractures for optimal reservoir management.
In reservoirs producing primarily from secondary porosity like fractures, the flow is largely controlled by the fracture system and characterizing these fractures is key to effectively managing these reservoirs. Aligned fractures will affect the average stiffness of the rocks even when fractures are smaller than seismic wavelengths. Small scale aligned fractures lead to variations in the seismic velocities that are directionally dependent, an effect known as anisotropy. Measuring this seismic anisotropy provides information on the fracture systems properties, such as fracture density and orientation. Such information can be used to identify sweet spots and in general be used for better reservoir management, like guiding directional and infill drilling.
Since fractures are often nearly vertical to bedding the dominant seismic effect is azimuthal anisotropy, which is observed both on P- and S-waves. AVOA (azimuthal AVO-effect) and variations in the NMO velocities have been used to estimate P-wave anisotropy. S-waves will split into one fast and one slow mode and this splitting is very sensitive to small changes in the subsurface. The fast shear-wave direction aligns with the fracture strike and the amount of time splitting between the fast and slow mode depends on fracture density. Apart from the difference in sensitivity between the P- and S-wave measurements there are attributes of the fracture system that can only be observed on the S-wave data. The asymmetry in the converted waves (PS-data) can say something about the tilt of the fractures. Multicomponent seismic provides access to both the P- and S-wave azimuthal information. Combining these two can enable the extraction of information about the fluid in the fractures. In this paper we will give an overview of the theory and several cases where multi-component data has been used to characterize fractures and fracture attributes.
Artificial Neural Networks Models for Predicting PVT Properties of Oil Field Brines
Authors: Osman E. A. , Al-Marhoun M. A. 
Published: December 2007

Abstract
Knowledge of chemical and physical properties of formation water is very important in various reservoir engineering computations especially in water flooding and production. Ideally, those data should be obtained experimentally. On some occasions, these data are not either available or reliable; then, empirically derived correlations are used to predict brine PVT properties. These correlations offer a handy and an acceptable approximation of formation water properties. However, the success of such correlations in prediction depends mainly on the range of data at which they were originally developed. These correlations were developed using linear, non-linear, multiple regression or graphical techniques.
Recently, researchers utilized artificial neural networks (ANN) to develop more accurate oil PVT correlations. The developed models outperformed the existing correlations. However, there is no similar research done so far to utilize the power of ANN in developing similar models for formation waters. In the present study, two new models were developed to predict different brine properties. The first model predicts brine density, formation volume factor (FVF), and isothermal compressibility as a function of pressure, temperature and salinity. The second model is developed to predict brine viscosity as a function of temperature and salinity only. An attempt was made to develop a comprehensive model to predict all properties in terms of pressure, temperature and salinity. The results were satisfactory for all other properties except for viscosity. This was attributed to the fact that viscosity depends only on temperature and salinity. The models were developed using 1040 published data sets. These data were divided into three groups: training, cross-validation and testing. Radial Basis Functions (RBF) and Multi-layer Preceptor (MLP) neural networks were utilized in this study. Trend tests were performed to ensure that the developed model would follow the physical laws. Results show that the developed models outperform the published correlations in terms of absolute average percent relative error, correlation coefficient and standard deviation.
Mechanical Methods of Reducing Torque and Drag in Extended-Reach Wells Facilitate Continued Canadian Foothills Development
Authors: Berry M. , Dousett J. , Cowling D. 
Published: December 2007

Abstract
This paper examines the use of mechanical torque and drag reduction tools for overcoming drillstring limitations encountered while drilling extended-reach wells in the Waterton area of Alberta, Canada. Three highly deviated new wells and two extended-reach horizontal re-entries were drilled using the tools. The paper summarizes the challenges of drilling wells in this area, the use of an engineering software system to optimally position the mechanical torque and drag reduction tools in the drillstring, and the results achieved.
Case History: Using a Communications Protocol to Reduce Wiring Costs During Construction of Well Test Headers
Authors: Norman M. , Denke L. 
Published: December 2007

Abstract
We installed several systems that used Actuator Sensor Interface (ASi) bus to simplify and economize the wiring of valves on well test headers1 in California oilfields. Using a communication protocol like ASi bus (or DeviceNet) reduces the amount of wiring and conduit that must be purchased and installed for each well test header. We have achieved cost reductions by using ASi bus communication on well test headers. As with introduction of any new technology, there were numerous "lessons learned." We present our recommendations for installing ASi bus systems.
Investigations Into The Suitability Of Galvanic Cathodic Protection Systems For Long Term Protection Of Buried Pipelines In Desert Locations
Authors: Hawkyard J. , McGlone D. 
Published: December 2007

Proposal
The paper outlines the Khuff gas distribution system operated and maintained by The Bahrain Petroleum Company (BAPCO). It will detail the types of cathodic protection installed and areas of apparent premature failure of galvanic cathodic protection systems
In 1998 a number of new pipelines were installed and magnesium sacrificial anode systems designed and installed. At about the same time some remedial work was undertaken on existing pipelines to replace depleted magnesium anodes.
During a recent routine survey of the cathodic protection systems it was found that a number of these anodes had apparently failed prematurely and were not achieving proper protection levels.
The paper will outline investigations carried out into the failed anodes, reasons for failure and recommendations for remedial work.
This paper will focus on the use and suitability of sacrificial anode systems versus impressed current systems for the long-term cathodic protection of buried pipelines in desert and reclaimed land areas.
Nonconventional Medium-Wavelength Static-Correction Method to Overcome Shallow Gas Anomaly Problem
Authors: Noor Y. , de Tonnac G. , Bonnafé J. , Waluyo A. 
Published: December 2007

Abstract
Sisi and Nubi are two gas fields operated by Total E&P Indonésie, located 20 km offshore from the Mahakam Delta (East Kalimantan).
In order to design the future field development, a 1000 km2 3D seismic data set was acquired during 2003 that covered the field area and beyond. There are two main challenges in processing this data:
Push-down effects. This problem is well known in the Mahakam Delta area and is associated with shallow gas anomalies characterized by very low seismic velocities. Amplitude distortion. Shallow gas anomalies also act as amplitude masks
Total E&P Indonésie solved the problem using non conventional medium wavelength static corrections. The processing method was established using WesternGeco technology in cooperation with Total expertise.
Arthit Log-Derived Permeability Modeling Project
Authors: Stephens S. , Pisutha-Arnond S. , Schoenicke O. , Vatthanavit K. , Jiang L. 
Published: December 2007

Abstract
A log-derived permeability prediction model for the new Arthit Field in the Gulf of Thailand has been successfully developed based on available cores and well test results. Accounting for more rock and fluid parameters than just porosity alone, the log-based algorithm has proven to be better-equipped to predict permeability with less uncertainty than traditional K-PHI cross-plots. The Arthit permeability model considers not only porosity, but variations in clay mineral composition and clay volume.
It is a well-known fact that sands having the same porosity will not necessarily have the same permeability due to other reservoir factors affecting permeability. A traditional K-PHI cross-plot employing a straight-line correlation of permeability and porosity cannot be expected to provide the best estimate of rock permeability due its indifference to changes in the rock matrix. The Arthit log-derived permeability model (K-Log) considers not only porosity, but variations in clay mineral composition and clay volume. It eliminates the need to subdivide data by rock type, does not require a semi-log scale correlation, and reduces the uncertainty of prediction. Clay diagenesis and reservoir temperature were identified as important parameters affecting permeability where predictions in shallow, low-temperature zones poorly matched actual measurements but reliably matched measurements at higher temperatures.
The model currently contains vertical definition by geologic formation. Areal definition should be possible in the near future as more permeability measurements are gathered from various geologic areas within Arthit resulting in distinct mineral factor sets for major geologic areas such as graben, basement flank, or basement high. Engineering applications currently planned for permeability modeling include well completion design, high-CO2 gas blending, field production forecasting, sand control, and reservoir simulation.