Pioneer designs, drills, completes and maintains our wells to protect groundwater quality and meet or exceed regulatory requirements. Pioneer incorporates measures designed to minimize the risk of groundwater impact, including highly regulated casing and cement designs, safety and monitoring systems, and ensuring ample rock barriers between hydrocarbon and freshwater zones.
Texas regulations require wells be drilled using freshwater prior to reaching the base of protected groundwater. They also mandate that companies ensure the mechanical integrity of wellbore casing and utilize cement barriers. Pioneer performs mechanical integrity testing throughout the well’s production life cycle. In accordance with industry standards and best practices, we test the surface casing integrity on all wells we drill.
In addition to the traditional well integrity testing, Pioneer conducts formation integrity testing, an industry best practice. The process begins with isolating usable groundwater zones from the well operations by (1) setting three layers of protective casing from the surface to below usable groundwater resources; (2) circulating cement between the steel casings; and (3) placing cement between the outer casing and the rock formation. The cement is allowed to set before the start of the formation integrity test, where the wellbore is pressurized and monitored to verify isolation and protection. Once confirmed, the drilling operation proceeds to the total depth of the well where a traditional mechanical integrity test is performed.
During the well completion process, Pioneer installs pressure gauges to monitor the annular space between the inner and outer well casing. Pressure readings transmitted from these gauges are monitored 24/7 during the completions phase to ensure constant casing integrity and cement isolation verification throughout the entire job. Additional precautions are taken on the surface, including pressure alarms, pressure relief valves and the utilization of rigorous standard operating procedures. Pioneer monitors 100% of stimulated wells in this manner.
Once our wells move to the production phase, we actively manage well integrity with corrosion countermeasures through a cathodic protection program. Our engineers remotely monitor production well-casing pressures via our SCADA system. This is in addition to 44the periodic well-integrity tests mandated by the Texas Railroad Commission. Issues identified through active operational monitoring and testing are resolved through standard procedures and in coordination with the Texas Railroad Commission. Wells may then be included in an active monitoring program, on a case-by-case basis, to verify continued casing integrity. We will monitor, manage and test future wells using these same methods.