Performance of fractured vertical and horizontal wells /
This study is comprised of two parts as follows: (1) the
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1997.
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| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=739891911&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | This study is comprised of two parts as follows: (1) the problem of a rectangular reservoir produced by a vertical well with a finite conductivity vertical fracture that penetrates the formation width partially or fully, and (2) the transient pressure and rate performance of a longitudinally fractured horizontal well in anisotropic, high-permeability formations. The vertically fractured, vertical well problem has been addressed by several authors. Most of this work had been focused on the transient behavior of a fractured vertical well produced at constant rate. However, there has been little work on the performance of fractured wells produced under constant flowing pressure. The area of boundary dominated performance has been left aside. It is important to know the effects of limited fracture conductivity and partial fracture length for both constant rate and pressure production cases. It is also important to be able to estimate the boundary dominated performance, where the most common boundary condition is that of constant flowing pressure. The first part addresses the problem of the closed, rectangular, reservoir produced through a fractured vertical well using a combination of analytical and numerical solutions. The known analytical solutions describe the behavior of the system when the infinite conductivity fracture fully penetrates the formation width. These analytical solutions are extended to handle finite conductivity fractures that partially penetrate the width of the formation. This extension of the analytical solution is achieved through two pseudoskins. These pseudoskins are shown not to be additive and an empirical expression is developed to estimate the combined effect of fracture partial length and finite conductivity. The pseudoskins developed in this work are compared against those existing in the literature. The second part studies the transient behavior of a longitudinal fracture in a horizontal well using numerical simulation. The study corroborates the semi-analytical results recently published. The effects of vertical anisotropy are studied and it is shown that this fracture configuration overcome vertical anisotropy. The effects of vertical-tohorizontal anisotropy are investigated showing that the longitudinally fractured horizontal well outperforms an unfractured, optimally oriented horizontal well in isotropic formations but the benefits of fracturing reduced as the anisotropy increases and the reservoir thickness decreases. Finally, this work presents a coordinate transformation that allows for proper pressure and rate data analysis when permeability anisotropy exists. Under pen-permability anisotropy, the effective system behaves as having a fracture with a higher dimensionless fracture conductivity (i.e. shorter fracture). |
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| Item Description: | Vita. "Major Subject: Petroleum Engineering". |
| Physical Description: | xiii, 92 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references: pages 68-71. |