A Users Guide to Leak-off Test Procedures and Interpretation for Geothermal Wells

التفاصيل البيبلوغرافية
العنوان: A Users Guide to Leak-off Test Procedures and Interpretation for Geothermal Wells
المؤلفون: Wallis I, Pye, DS, Dempsey, David, Rowland, J
سنة النشر: 2023
المجموعة: University of Canterbury, Christchurch: UC Research Repository
مصطلحات موضوعية: Fracture gradient, stress analysis, pumping test, leak-off test, extended leak-off test, mud weight, tensile fracture, 37 - Earth sciences, 40 - Engineering::4019 - Resources engineering and extractive metallurgy
الوصف: Leak-off Tests (LOT) and Extended Leak-off Tests (XLOT) are conducted during drilling to verify the competence of the cement around a casing shoe and determine the maximum allowable mud weight for the next hole section. (X)LOT interpretation yields the fracture gradient, which is a key parameter in well control procedures, mud program design and cement operations. These data are also one of the minimum requirements for any geomechanical study that seeks to understand the role fractures play in reservoir permeability. Despite its utility for successful well completion and studies investigating reservoir permeability, (X)LOT procedures are often poorly implemented and the interpretation methods used are not always appropriate for geothermal conditions. Using a case study, we describe the test procedures and interpretation process for typical geothermal conditions. We address key issues that set geothermal apart from oil and gas, such as the impact of high temperatures on test results, the high frequency of naturally occurring fractures, and the variable physical properties of hydrothermally altered volcanic rocks. We illustrate the impact of quality checking an existing (X)LOT dataset and review methods for estimating the fracture gradient prior to drilling in extensional environments. While our paper addresses a number of detailed technical issues related to interpretation, it aims to be a pragmatic and geothermally-relevant guide for those who aspire to improve the quality of these tests.
نوع الوثيقة: conference object
وصف الملف: application/pdf
اللغة: English
Relation: Wallis I, Pye DS, Dempsey D, Rowland J (2021). A Users Guide to Leak-off Test Procedures and Interpretation for Geothermal Wells. Reykjavik, Iceland: World Geothermal Congress.; https://hdl.handle.net/10092/106196
الاتاحة: https://hdl.handle.net/10092/106196
Rights: All rights reserved unless otherwise stated ; http://hdl.handle.net/10092/17651
رقم الانضمام: edsbas.CA006AA8
قاعدة البيانات: BASE