Interpretation, Analysis and Design of Inter-well Tracer Tests in Naturally Fractured Reservoirs

Interpretation, Analysis and Design of Inter-well Tracer Tests in Naturally Fractured Reservoirs PDF Author: Aymen Abduljalil Alramadhan
Publisher:
ISBN:
Category :
Languages : en
Pages : 311

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Book Description
In order to understand the complex fracture network that controls water movement in Sherrod Area of Spraberry Field in West Texas and to better manage the on-going waterflood performance, a field scale inter-well tracer test was implemented. This test presents the largest inter-well tracer test in naturally fractured reservoirs reported in the industry and includes the injection of 13 different tracers and sampling of 110 producers in an area covering 6533 acres. Sherrod tracer test generated a total of 598 tracer responses from 51 out of the 110 sampled producers. Tracer responses showed a wide range of velocities from 14 ft/day to ultra-high velocities exceeding 10,000 ft/day with same-day tracer breakthrough. Re-injection of produced water has caused the tracers to be re-injected and added an additional challenge to diagnose and distinguish tracer responses affected by water recycling. Historical performance of the field showed simultaneous water breakthrough of a large number of wells covering entire Sherrod area. This research investigate analytical, numerical, and inversion modeling approaches in order to categorize, history match, and connect tracer responses with water-cut responses with the objective to construct multiple fracture realizations based entirely on water-cut and tracers' profiles. In addition, the research highlight best practices in the design of inter-well tracer tests in naturally fractured reservoirs through lessons learned from Sherrod Area. The large number of tracer responses from Sherrod case presents a case of naturally fractured reservoir characterization entirely based on dynamic data. Results indicates that tracer responses could be categorized based on statistical analysis of tracer recoveries of all pairs of injectors and producers with each category showing distinguishing behavior in tracers' movement and breakthrough time. In addition, it showed that tracer and water-cut responses in the field are dominantly controlled by the fracture system revealing minimum information about the matrix system. Numerical simulation studies showed limitation in dual porosity formulation/solvers to model tracer velocities exceeding 2200 ft/day. Inversion modeling using Gradzone Analysis showed that east and north-west of Sherrod have significantly lower pore volume compared to south-west. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/151192

Interpretation, Analysis and Design of Inter-well Tracer Tests in Naturally Fractured Reservoirs

Interpretation, Analysis and Design of Inter-well Tracer Tests in Naturally Fractured Reservoirs PDF Author: Aymen Abduljalil Alramadhan
Publisher:
ISBN:
Category :
Languages : en
Pages : 311

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Book Description
In order to understand the complex fracture network that controls water movement in Sherrod Area of Spraberry Field in West Texas and to better manage the on-going waterflood performance, a field scale inter-well tracer test was implemented. This test presents the largest inter-well tracer test in naturally fractured reservoirs reported in the industry and includes the injection of 13 different tracers and sampling of 110 producers in an area covering 6533 acres. Sherrod tracer test generated a total of 598 tracer responses from 51 out of the 110 sampled producers. Tracer responses showed a wide range of velocities from 14 ft/day to ultra-high velocities exceeding 10,000 ft/day with same-day tracer breakthrough. Re-injection of produced water has caused the tracers to be re-injected and added an additional challenge to diagnose and distinguish tracer responses affected by water recycling. Historical performance of the field showed simultaneous water breakthrough of a large number of wells covering entire Sherrod area. This research investigate analytical, numerical, and inversion modeling approaches in order to categorize, history match, and connect tracer responses with water-cut responses with the objective to construct multiple fracture realizations based entirely on water-cut and tracers' profiles. In addition, the research highlight best practices in the design of inter-well tracer tests in naturally fractured reservoirs through lessons learned from Sherrod Area. The large number of tracer responses from Sherrod case presents a case of naturally fractured reservoir characterization entirely based on dynamic data. Results indicates that tracer responses could be categorized based on statistical analysis of tracer recoveries of all pairs of injectors and producers with each category showing distinguishing behavior in tracers' movement and breakthrough time. In addition, it showed that tracer and water-cut responses in the field are dominantly controlled by the fracture system revealing minimum information about the matrix system. Numerical simulation studies showed limitation in dual porosity formulation/solvers to model tracer velocities exceeding 2200 ft/day. Inversion modeling using Gradzone Analysis showed that east and north-west of Sherrod have significantly lower pore volume compared to south-west. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/151192

Well Test Analysis for Fractured Reservoir Evaluation

Well Test Analysis for Fractured Reservoir Evaluation PDF Author: G. Da Prat
Publisher: Elsevier
ISBN: 0080868851
Category : Technology & Engineering
Languages : en
Pages : 221

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Book Description
The main purpose of this book is to provide the reader with a basic understanding of the behaviour of fractured reservoirs, using evaluation techniques based on processing pressure and flow-rate data resulting from production testing.It covers the fundamental reservoir engineering principles involved in the analysis of fluid flow through fractured reservoirs, the application of existing models to field cases, and the evaluation and description of reservoirs, based on processed data from pressure and production tests. The author also discusses production decline analysis, the understanding of which is a key factor influencing completion or abandonment of a well or even a field.The theoretical concepts are presented as clearly and simply as possible in order to aid comprehension. The book is thus suitable for training and educational purposes, and will help the reader who is unfamiliar with the subject acquire the necessary skills for successful interpretation and analysis of field data.One of the most important features of the book is that it fills the gap between field operations and research, in regard to proper management of reservoirs. The book also contains a computer program (FORTRAN language) which can be incorporated in existing software designed for reservoir evaluation; type curves generation, test design and interpretation, can be achieved by using this program.Petroleum engineers, reservoir engineers, petroleum geologists, research engineers and students in these fields, will be interested in this book as a reference source. It can also be used as a text book for training production and reservoir engineering professionals. It should be available in university and oil company libraries.

Dynamic Reservoir Characterization Of Naturally Fractured Reservoirs From An Inter-Well Tracer Test

Dynamic Reservoir Characterization Of Naturally Fractured Reservoirs From An Inter-Well Tracer Test PDF Author: Ufuk Kilicaslan
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
After field redevelopment in the Sherrod Unit of the Spraberry Trend Area, an inter-well tracer test was conducted at the field scale in order to understand the fracture system, which forms preferential flow paths for better management of waterflooding. The test consisted of 13 injection wells and more than 110 producing wells that were sampled, with each injector having its own unique tracer. A wide range of tracer responses was observed in terms of tracer recovery, breakthrough time, and tracer velocity. Additional noise on tracer data was noticed due to reinjection of produced water. In this study, a comprehensive workflow is presented for dynamic reservoir characterization of naturally fractured reservoirs from an inter-well tracer test by incorporation of analytical interpretation, streamline simulation, and streamline-based optimization techniques. Categorized tracer responses were mapped according to analytical analysis, and dominating flow trends were detected in E-W and NE-SW directions before the simulation study. The constructed three-phase, dual-porosity model was simulated by a streamline simulator. Certain parameters in the model were modified based on high tracer response until a reasonable match was obtained for an inverted nine-spot pattern and breakthrough time of the injected tracer. Once the model became capable of matching historical field production, a 1-year prediction run was conducted for optimization. Cumulative oil production was increased by 8,000 bbl by allocating more water toward efficient producers, and 10,000 bbl less water was produced for the optimized case. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/151965

Novel, Integrated and Revolutionary Well Test Interpretation and Analysis

Novel, Integrated and Revolutionary Well Test Interpretation and Analysis PDF Author: Freddy Escobar
Publisher: BoD – Books on Demand
ISBN: 1789848504
Category : Technology & Engineering
Languages : en
Pages : 296

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Book Description
The TDS technique is a practical, easy, and powerful tool for well test interpretation. It uses characteristic features and points found on the pressure derivative versus time plot, so that reservoir parameters can be easily calculated by using several analytic expressions. Most calculations can be verified more than once and applied to systems where the conventional straight-line method has no applications. This book deals with well tests run in elongated systems, partially completed/penetrated wells, multirate tests, hydraulically fractured wells, interference tests, and naturally fractured reservoirs. This technique is used in all commercial well-testing software. Its use is the panacea for well test interpretation and can also be extended to rate-transient analysis, although not shown here.

Well Test Analysis

Well Test Analysis PDF Author: Dominique Bourdet
Publisher: Elsevier
ISBN: 0080543774
Category : Technology & Engineering
Languages : en
Pages : 439

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Book Description
This book on well test analysis, and the use of advanced interpretation models is volume 3 in the series Handbook of Petroleum Exploration and Production.The chapters in the book are: Principles of Transient Testing, Analysis Methods, Wellbore Conditions, Effect of Reservoir Heterogeneities on Well Responses, Effect of Reservoir Boundaries on Well Responses, Multiple Well Testing, Application to Gas Reservoirs, Application to Multiphase Reservoirs, Special Tests, Practical Aspects of Well Test Interpretation.

AN INTEGRATED APPROACH TO CHARACTERIZING BYPASSED OIL IN HETEROGENEOUS AND FRACTURED RESERVOIRS USING PARTITIONING TRACERS.

AN INTEGRATED APPROACH TO CHARACTERIZING BYPASSED OIL IN HETEROGENEOUS AND FRACTURED RESERVOIRS USING PARTITIONING TRACERS. PDF Author: Akhil Datta-Gupta
Publisher:
ISBN:
Category :
Languages : en
Pages : 77

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Book Description
We explore the use of efficient streamline-based simulation approaches for modeling partitioning interwell tracer tests in hydrocarbon reservoirs. Specifically, we utilize the unique features of streamline models to develop an efficient approach for interpretation and history matching of field tracer response. A critical aspect here is the underdetermined and highly ill-posed nature of the associated inverse problems. We have adopted an integrated approach whereby we combine data from multiple sources to minimize the uncertainty and non-uniqueness in the interpreted results. For partitioning interwell tracer tests, these are primarily the distribution of reservoir permeability and oil saturation distribution. A novel approach to multiscale data integration using Markov Random Fields (MRF) has been developed to integrate static data sources from the reservoir such as core, well log and 3-D seismic data. We have also explored the use of a finite difference reservoir simulator, UTCHEM, for field-scale design and optimization of partitioning interwell tracer tests. The finite-difference model allows us to include detailed physics associated with reactive tracer transport, particularly those related with transverse and cross-streamline mechanisms. We have investigated the potential use of downhole tracer samplers and also the use of natural tracers for the design of partitioning tracer tests. Finally, the behavior of partitioning tracer tests in fractured reservoirs is investigated using a dual-porosity finite-difference model.

An Integrated Approach to Characterizing Bypassed Oil in Heterogeneous and Fractured Reservoirs Using Partitioning Tracers

An Integrated Approach to Characterizing Bypassed Oil in Heterogeneous and Fractured Reservoirs Using Partitioning Tracers PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
We explore the use of efficient streamline-based simulation approaches for modeling partitioning interwell tracer tests in hydrocarbon reservoirs. Specifically, we utilize the unique features of streamline models to develop an efficient approach for interpretation and history matching of field tracer response. A critical aspect here is the underdetermined and highly ill-posed nature of the associated inverse problems. We have investigated the relative merits of the traditional history matching ('amplitude inversion') and a novel travel time inversion in terms of robustness of the method and convergence behavior of the solution. We show that the traditional amplitude inversion is orders of magnitude more non-linear and the solution here is likely to get trapped in local minimum, leading to inadequate history match. The proposed travel time inversion is shown to be extremely efficient and robust for practical field applications. The streamline approach is generalized to model water injection in naturally fractured reservoirs through the use of a dual media approach. The fractures and matrix are treated as separate continua that are connected through a transfer function, as in conventional finite difference simulators for modeling fractured systems. A detailed comparison with a commercial finite difference simulator shows very good agreement. Furthermore, an examination of the scaling behavior of the computation time indicates that the streamline approach is likely to result in significant savings for large-scale field applications. We also propose a novel approach to history matching finite-difference models that combines the advantage of the streamline models with the versatility of finite-difference simulation. In our approach, we utilize the streamline-derived sensitivities to facilitate history matching during finite-difference simulation. The use of finite-difference model allows us to account for detailed process physics and compressibility effects. The approach is very fast and avoids much of the subjective judgments and time-consuming trial-and-errors associated with manual history matching. We demonstrate the power and utility of our approach using a synthetic example and two field examples. We have also explored the use of a finite difference reservoir simulator, UTCHEM, for field-scale design and optimization of partitioning interwell tracer tests. The finite-difference model allows us to include detailed physics associated with reactive tracer transport, particularly those related with transverse and cross-streamline mechanisms. We have investigated the potential use of downhole tracer samplers and also the use of natural tracers for the design of partitioning tracer tests. Finally, we discuss several alternative ways of using partitioning interwell tracer tests (PITTs) in oil fields for the calculation of oil saturation, swept pore volume and sweep efficiency, and assess the accuracy of such tests under a variety of reservoir conditions.

Novel, Integrated and Revolutionary Well Test Interpretation and Analysis

Novel, Integrated and Revolutionary Well Test Interpretation and Analysis PDF Author: Freddy Humberto Escobar Macualo
Publisher:
ISBN: 9781789848519
Category : Hydraulic engineering
Languages : en
Pages : 294

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Book Description
The TDS technique is a practical, easy, and powerful tool for well test interpretation. It uses characteristic features and points found on the pressure derivative versus time plot, so that reservoir parameters can be easily calculated by using several analytic expressions. Most calculations can be verified more than once and applied to systems where the conventional straight-line method has no applications. This book deals with well tests run in elongated systems, partially completed/penetrated wells, multirate tests, hydraulically fractured wells, interference tests, and naturally fractured reservoirs. This technique is used in all commercial well-testing software. Its use is the panacea for well test interpretation and can also be extended to rate-transient analysis, although not shown here.

Simulating Water Tracer Test in Naturally Fractured Reservoirs Using Discrete Fracture and Dual Porosity Models

Simulating Water Tracer Test in Naturally Fractured Reservoirs Using Discrete Fracture and Dual Porosity Models PDF Author: Farshad Lalehrokh
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
A naturally fractured reservoir (NFR) is a reservoir with a connected network of fractures created by natural processes such as diastrophism and volume shrinkage (Ordonez et al. 2001). There are two models to simulate this kind of reservoirs: the discrete fracture model and the dual porosity model. In the dual porosity model, the matrix blocks occupy the same physical space as the fracture network and are identical rectangular parallelepipeds with no direct communication between isotropic and homogeneous matrix blocks. However, each fracture and matrix property is defined separately in the discrete fracture model. Another feature of this thesis is tracer testing. In this process, a chemical or radioactive element is injected to the reservoirs, and then it can be traced using the devices, which are designed to detect the tracers. Tracer tests have several advantages such as determining residual oil saturation, identifying barriers or high permeability zones in reservoirs, and providing the information on flow patterns. Limited number of research studies has been done on performing tracer tests in naturally fractured reservoirs. Also because there is not enough information about the advantages and disadvantages of the discrete fracture and the dual porosity models, researchers and engineers lack the expertise to confidently select either the discrete fracture or the dual porosity models to simulate the different types of NFRs. In this thesis, we compared the oil and water productions, and tracer concentration curves in various reservoir conditions, using both the discrete fracture and the dual porosity models. We used the ECLIPSE, which is a commercial software package in the area of petroleum industry, to model a naturally fractured reservoir. We performed a simple waterflooding with two conservative tracers on the reservoirs. The results presented in each section include the graphs of the oil production rate, water production rate, and tracer concentration. In addition, we presented the oil saturation profiles of a cross-section, which includes the production and injection wells. The results illustrated that both the discrete fracture and the dual porosity models are in good agreement, except for a few special cases. Generally, the oil production using the dual porosity model is more than in the discrete fracture model. The major disadvantage of the dual porosity model is that the fluid distribution in the matrix blocks is changing homogenously during the waterflooding period. In other words, ECLIPSE shows a constant value of the oil and water saturations in each time step for the matrix blocks. However, the dual porosity model is 3 to 4 times faster than the discrete fracture model. In the discrete fracture model, the users have complete control in defining the reservoirs. For example, the fracture aperture, fracture spacing, and fracture porosities can be set by the user. The disadvantage of this model is that millions of grid blocks are needed to model a large reservoir with small fracture spacing.

Well Test Analysis

Well Test Analysis PDF Author: Mohamed A. Sabet
Publisher: Gulf Professional Publishing
ISBN:
Category : Science
Languages : en
Pages : 510

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Book Description
For engineers in the petroleum industry using test wells to evaluate the economic feasibility of drilling a production well into a particular reservoir. Details the mathematics and interpretations of a number of testing methods drawdown, pressure buildup, multirate flow, and wellbore effects; review