Studying the impact of thermal cycling on wellbore integrity during CO2 injection

Pratanu Roy, Stuart D.C. Walsh, Joseph P. Morris, Jaisree Iyer, Yue Hao, Susan Carroll, Kamila Gawel, Jelena Todorovic, Malin Torsæter

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearchpeer-review

11 Citations (Scopus)

Abstract

Injection of supercritical CO2 into storage reservoirs causes thermally induced expansion and contraction inside the wellbore, potentially leading to the creation of leakage pathways. Determining a safe operating range for temperature and assessment of thermal stresses during CO2 injection is essential to ensure wellbore integrity. Although failure of well barrier materials, such as steel and cement, has been reported in the contemporary literature, most of these studies applied purely mechanical loads to replicate thermally induced stresses. Thus, a systematic investigation of thermally induced casing expansion and contraction affecting the cracking and debonding of the well barrier materials is yet to be performed. In this work, we have applied a combination of experiments and simulations to analyze the thermo-mechanical behavior of the well barrier materials undergoing repeated thermal cycling. The objectives of these studies are to determine when fracturing or debonding occurs as a function of applied thermal cycles and time, where these defects appear, and how prevalent or extensive they are. The experiments were performed in the SINTEF Petroleum Research laboratory using downscaled wellbore samples, consisting of a steel pipe cemented inside a hollow sandstone cylinder. The effects of thermal cycling were visualized using X-ray computed tomography to determine the extent of fracture. The simulations were conducted at the Lawrence Livermore National Laboratory using a highly parallel, multiscale, multiphysics code named GEOS. The experimental results did not show any detectable change in the existing pore volume of the sample for a temperature range between-50°C to 80°C. However, the simulation results suggest that large thermal stresses can develop inside the materials, which may create radial fractures/debonding during the heating/cooling stage. The data gathered from these experiments and simulations can be used to assess the temperature range for minimal impact on well integrity.

Original languageEnglish
Title of host publication50th US Rock Mechanics / Geomechanics Symposium 2016
PublisherAmerican Rock Mechanics Association (ARMA)
Pages3411-3422
Number of pages12
Volume4
ISBN (Electronic)9781510828025
Publication statusPublished - 1 Jan 2016
Externally publishedYes
EventUS Rock Mechanics / Geomechanics Symposium 2016 - Houston, United States of America
Duration: 26 Jun 201629 Jun 2016
Conference number: 50th

Conference

ConferenceUS Rock Mechanics / Geomechanics Symposium 2016
CountryUnited States of America
CityHouston
Period26/06/1629/06/16

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