Field experience and numerical investigations of minifrac tests with flowback in low-permeability formations

In this study, flowback-assisted minifrac tests were conducted in low-permeability shale and salt formations to measure the in situ stress. An injection/flowback testing protocol was implemented in each test to achieve accuracy and efficiency. Accurate and efficient injection/flowback testing is ver...

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Main Authors: Yu Fan, Rui Yong, Bo Zeng, Yi Song, Xiaojin Zhou, Bin Xu
Format: Article
Language:English
Published: KeAi Communications Co., Ltd. 2021-06-01
Series:Underground Space
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2467967420300052
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author Yu Fan
Rui Yong
Bo Zeng
Yi Song
Xiaojin Zhou
Bin Xu
author_facet Yu Fan
Rui Yong
Bo Zeng
Yi Song
Xiaojin Zhou
Bin Xu
author_sort Yu Fan
collection DOAJ
description In this study, flowback-assisted minifrac tests were conducted in low-permeability shale and salt formations to measure the in situ stress. An injection/flowback testing protocol was implemented in each test to achieve accuracy and efficiency. Accurate and efficient injection/flowback testing is very important, given the impermeable nature of these formations and the need to complete each test as quickly as possible. Each flowback cycle yields a distinct and repeatable fracture closure signature, simplifying the interpretation of the fracture closure pressure. The objective of this paper is to share our field experience and to present a numerical analysis of the flowback test pressure responses, fracture closure behaviors, and fracture closure diagnostic methods. Examples from open-hole and cased-hole minifrac tests are used to demonstrate site operation procedures. Then, two numerical models are presented for simulating the fracture closure behavior during a flowback test. Field evidence is provided to demonstrate that the fracture closure pressures from the flowback tests are identical to those from tests without flowback. The fracture closure diagnostic methods for flowback tests are discussed, and it is found that the G-function diagnostic method yields a distinct fracture closure signal during the flowback tests. This study is intended to provide additional insights regarding flowback tests by sharing our successes, experience, and knowledge, thereby benefiting the industry.
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spelling doaj.art-6f52b318653b4ac594afeae81e8e87d12023-09-02T07:41:11ZengKeAi Communications Co., Ltd.Underground Space2467-96742021-06-0163300315Field experience and numerical investigations of minifrac tests with flowback in low-permeability formationsYu Fan0Rui Yong1Bo Zeng2Yi Song3Xiaojin Zhou4Bin Xu5Shale Gas Research Institute of PetroChina Southwest Oil and Gas Field Company, Chengdu 610051, ChinaShale Gas Research Institute of PetroChina Southwest Oil and Gas Field Company, Chengdu 610051, ChinaShale Gas Research Institute of PetroChina Southwest Oil and Gas Field Company, Chengdu 610051, ChinaShale Gas Research Institute of PetroChina Southwest Oil and Gas Field Company, Chengdu 610051, ChinaShale Gas Research Institute of PetroChina Southwest Oil and Gas Field Company, Chengdu 610051, ChinaOrigin Geomechanics Inc., Calgary T3H 0X6, Canada; Concordia University, Montreal, Quebec H3G 1M8, Canada; Corresponding author at: Origin Geomechanics Inc., Calgary T3H 0X6, Canada.In this study, flowback-assisted minifrac tests were conducted in low-permeability shale and salt formations to measure the in situ stress. An injection/flowback testing protocol was implemented in each test to achieve accuracy and efficiency. Accurate and efficient injection/flowback testing is very important, given the impermeable nature of these formations and the need to complete each test as quickly as possible. Each flowback cycle yields a distinct and repeatable fracture closure signature, simplifying the interpretation of the fracture closure pressure. The objective of this paper is to share our field experience and to present a numerical analysis of the flowback test pressure responses, fracture closure behaviors, and fracture closure diagnostic methods. Examples from open-hole and cased-hole minifrac tests are used to demonstrate site operation procedures. Then, two numerical models are presented for simulating the fracture closure behavior during a flowback test. Field evidence is provided to demonstrate that the fracture closure pressures from the flowback tests are identical to those from tests without flowback. The fracture closure diagnostic methods for flowback tests are discussed, and it is found that the G-function diagnostic method yields a distinct fracture closure signal during the flowback tests. This study is intended to provide additional insights regarding flowback tests by sharing our successes, experience, and knowledge, thereby benefiting the industry.http://www.sciencedirect.com/science/article/pii/S2467967420300052In situ stress determinationMinifracFlowbackFracture closure diagnostic methodNumerical simulations
spellingShingle Yu Fan
Rui Yong
Bo Zeng
Yi Song
Xiaojin Zhou
Bin Xu
Field experience and numerical investigations of minifrac tests with flowback in low-permeability formations
Underground Space
In situ stress determination
Minifrac
Flowback
Fracture closure diagnostic method
Numerical simulations
title Field experience and numerical investigations of minifrac tests with flowback in low-permeability formations
title_full Field experience and numerical investigations of minifrac tests with flowback in low-permeability formations
title_fullStr Field experience and numerical investigations of minifrac tests with flowback in low-permeability formations
title_full_unstemmed Field experience and numerical investigations of minifrac tests with flowback in low-permeability formations
title_short Field experience and numerical investigations of minifrac tests with flowback in low-permeability formations
title_sort field experience and numerical investigations of minifrac tests with flowback in low permeability formations
topic In situ stress determination
Minifrac
Flowback
Fracture closure diagnostic method
Numerical simulations
url http://www.sciencedirect.com/science/article/pii/S2467967420300052
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