Well integrity is a fundamental defense against water contamination. Subsurface evaluations conducted by our geologists and engineers before drilling are used to determine the depths of formations that contain underground drinking water, the proximity of that water to potential oil and natural gas intervals and the integrity of the confining layers above and below the target completion zone. The casing and cementing plan for well construction incorporates these factors into the well design.
Multiple strings of casing and cement are used to prevent natural gas migration or water contamination. We monitor pump pressures and fluid returns during the cementing process to ensure full coverage of cement across the production and groundwater zones. The mechanical integrity of the casing and cement is tested to ensure proper installation at multiple stages of the drilling and completion process, using techniques such as pressure testing, and wire line and bond logging. Well control procedures are in place to prevent events such as spills. During the production phase, we continuously monitor flow rates and annular pressures, and we regularly inspect the wellhead assembly and other equipment for leaks, corrosion or damage.