Particle Size Distribution-Engineered Cementing Approach Reduces Need for Polymeric Extenders in Haynesville Shale Horizontal Reach Wells

摘要

Recently discovered Haynesville gas-shale trends have transformed the regional and global outlook for natural gas supply, but offer unique challenges to the operator and service company during mud removal, cementing, and completion operations. To counter these challenges, recent advances include improved drilling, centralization, mud-removal, cementing best practices and implementing a broad particle size distribution– engineered (PSDE) cement system for use in high temperature horizontal intervals reaching across high pressure, high temperature (HPHT) gas-shale trends. For PSDE cement systems, rheological properties are based on inter-particulate interactions to achieve the desired viscosity and not based on polymeric extenders/antisettling additives. Since PSDE fluids are not dependent on polymeric thermal thinning behavior, they demonstrate consistent rheological properties over a wide temperature range and are more suitable for placement in narrow annuli. In this paper, Haynesville cement placement and extensive laboratory testing best practices will be discussed. Also, a case study will be presented that describes a typical and successful placement of PSDE cement fluid in the Haynesville shale at bottom hole circulating temperatures (BHCT) up to 182 °C [360°F] and bottom hole pressures (BHP) up to 82.7 MPa [12,000 psi]. After successful job completion and time allowed for the cement to properly set, an annular seal pressure test was successfully completed, with minimal pressure bleed-off. Since introduction in 2009, over 390 production jobs have been successfully cemented using the PSDE cement technology, with 99.5% placement success rate. Acquired well head pressures (WHP) were less than or equal to predicted WHP for most production jobs. PSDE Cement Technology has become a proven approach for cementing high-temperature, horizontal tight- gas shale environments in relatively narrow annuli where fluid stability and zonal isolation are needed during placement and subsequent hydraulic fracturing treatments. This approach has been applied to Haynesville and Eagleford shale horizontal reach production wells and is being investigated for use in other high temperature, high pressure applications.