Development of a New Retarder Recipe Containing Boric Acid for Improved Performance Efficiency at Mid Temperature Range (MTR) in Oil and Gas Well Cementing Operations

Abstract

Various cementing retarders used in field operations where the Bottom Hole Circulation Temperatures (BHCTs) are in the range of 240F to 280F have been observed to pose deficiencies like the inability to adequately cover the entire temperature spectrum, especially towards its higher end. This study recommends a recipe that has more reliability across the entire temperature range. API 10B-2 was adopted as the method of choice during the study's laboratory analysis. The thickening times for various concentrations of existing widely used mid-temperature retarders were analyzed to find out the temperature range in which the retarder works with its optimum performance efficiency. Then, the recommended recipe which combines Boric acid, and a lignosulfonate-based product was subjected to the same test conditions to reveal the maximum attainable temperature. These results were compared to show which recipe had the optimum performance. The laboratory results obtained showed that despite the increasing concentrations of the reference mid-temperature retarders (MTRs), which were tested at different mid-temperatures, it was not possible to achieve extended thickening times especially as the test temperatures approached the higher end of the temperature spectrum (260F-280F); Some reference retarders, despite their claims to be used as MTRs, could not be used to design extended thickening time above 220F, others which were reliable at the lower end of the temperature spectrum, lost desired efficiency as the test temperatures increased up to 250F. However, the recommended recipe under study which combines a fixed concentration of the lignosulfonate-based product and varying concentrations of Boric acid was effectively reliable with better thickening time performance across the entire temperature spectrum from 240F to 280F. This development introduces to the industry a reliable Mid Temperature Retarder (MTR) recipe that covers the entire spectrum of the mid-temperature range and allows for the design of both short and long thickening times.