Industrial Standard for Testing Well-Abandonment Materials Is Essential for Well Integrity
Authors: Carpenter Chris 
Published: January 2025

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This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 217934, “Raising the Bar: Why an Industrial Standard for Testing Hydraulic Sealability of Well-Abandonment Materials in Laboratory Is Essential for Well Integrity,” by Ragnhild Skorpa, SPE, and Nils Opedal, SPE, SINTEF, and Mahmoud Khalifeh, SPE, University of Stavanger, et al. The paper has not been peer reviewed.

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Advances in the properties of ordinary Portland cement (OPC) and new materials have shifted the focus of research and development toward sealing capability of plugging materials at interfaces between the material and its adjacent medium. The objective of the complete paper is to outline the importance of new standards for studying hydraulic sealability of barrier materials, with emphasis on interface analysis. The authors conclude that it would be highly beneficial for current standards to be updated to include sealability analysis and the updated standards be implemented for new and alternative materials such as geopolymers, settled barite, and metal alloys.

Introduction

Extensive research and characterization of the shear bond between cement and the adjacent medium, particularly in cases where the adjacent medium is the casing, have been rigorously conducted. Despite comprehensive research efforts and engineering undertakings concerning the study of the shear bond and hydraulic sealability of solidified cement, however, the absence of standardized testing protocols remains conspicuous. This lack of standardization can be attributed primarily to the inconsistent nature of the conducted research and the various contributing factors that significantly affect the performance of OPC.

The scope of this study is to conduct a comprehensive review of previous research endeavors concerning the hydraulic sealability of cement. This review is contained in the complete paper, with this synopsis concentrating on a discussion of more-standardized testing beyond the current API RP 10B. The review seeks to shed light on the various experimental setups and test protocols used, thereby identifying the barriers that have hindered the establishment of standardized test protocols. The central focus of the review lies in the meticulous examination of experiments carried out in both small-scale and medium-scale test setups, with an emphasis on delineating the pivotal contributing factors.

Discussion

General Principles of Setup Design.

Experimental testing on hydraulic sealability aims to simulate the phenomenon and conditions in the wellbore. The goal of these measurements is to apply a differential pressure across the cement plug and monitor either the flow rate or decrease in pressure. The basic components necessary for performing these tests are a source of pressure mimicking the pressure difference between the reservoir and overlying zones, a cell containing the materials that are mimicking the wellbore configuration, and equipment to monitor either pressure or flow rates. Whether this basic setup contains monitoring of pressure or flow dictates the measurement protocol.