Development of a New Retarder Recipe Containing Boric Acid, Which Exhibits Excellent Mechanical Properties Suited for the Mid Temperature Range (MTR) in Oil and Gas Well Cementing Operations

Abstract

In field operations with Bottom Hole Circulation Temperatures (BHCTs) ranging from 240F to 280F, a range of cementing retarders have been noted to exhibit shortcomings, particularly in their ability to effectively address the entire temperature range, particularly at the higher end. This research proposes a formula that offers greater consistency, reliability, and excellent mechanical properties throughout the entire temperature spectrum. During the laboratory analysis of this study, the API 10B-2 method was selected as the preferred approach. This method was used to examine the thickening times associated with different concentrations of commonly employed mid-temperature retarders, with the aim of determining the temperature range at which the retarder exhibits its best performance efficiency. Subsequently, the recommended recipe, which combines Boric acid and a lignosulfonate-based product, was subjected to the same testing conditions to determine the highest achievable temperature at which it remains effective. The mechanical properties of the proposed recipe were also determined and compared to the industry minimum requirements. The laboratory findings indicated that, when testing various concentrations of the reference mid-temperature retarders (MTRs) at different mid-temperatures, it was challenging to achieve extended thickening times, especially as the test temperatures approached the higher end of the spectrum (260F-280F). Some of these reference retarders, despite their claims to be suitable for mid-temperature use, fell short in extending thickening times beyond 220F. Others, which performed well at lower temperatures, lost their desired efficiency as the test temperatures increased, reaching up to 250F. However, the recommended recipe under investigation, which combines a consistent concentration of the lignosulfonate-based product with varying levels of Boric acid, proved to be reliably effective with improved thickening time performance across the entire temperature range, spanning from 240F to 280F, as well as satisfying and exceeding the minimum required mechanical properties in the industry. This advancement introduces an industry-dependable mid-temperature retarder (MTR) formula that spans the entire mid-temperature range, enabling the design of both shorter and longer thickening times as needed which satisfies the minimum required mechanical properties for oil and gas well cement fluids.