A Comprehensive Test Pad for Bradenhead Pressure Mitigation in the DJ Basin

Abstract

Abstract Bradenhead pressure, or sustained casing pressure, is pressure build up in the annular space between the surface casing and the next smaller diameter casing string within the wellhead. The objective of the test pad was to determine if increasing the physical flexibility of cement and rotating the casing string to increase displacement efficiency would help improve the cement bond to casing, decrease cement channeling, and help eliminate future bradenhead pressure accumulation. A twelve well pad housed three different cement slurries: four latex-type jobs, four resin jobs, and four foam jobs. A rotating cement head was used to enable mud circulation, dropping plugs, and rotating the string of casing during the cementing process on two of the four wells of each slurry type. For the production casing string, a threaded and coupled connection with a wedge thread profile was used to withstand the high torque experienced during rotation operations. Results were determined by evaluating pre- and post-stimulation logs along with continued bradenhead pressure monitoring. According to the outcomes from this test pad, recommendations were made on cementing practices within the Denver-Julesburg (DJ) Basin, based on regional gas-oil ratios (GOR). This interdisciplinary work determined whether the deployment of advanced cement slurries and casing rotation would help eliminate a potential health, safety, and environment (HSE) risk and help improve well integrity as related to bradenhead pressure.