Posted: 1 week, 5 days ago
OIL AND GAS WELL PLUG AND ABANDONMENT
As the economic life of a well ends or for a commercially failed well (dry hole), the well must be placed in a safe condition. This is accomplished by plug and abandoning the well and this article provides a primer to how a well is plugged and abandoned (P&A). Well P&A have rules governing the process. Rules vary by governing standards and guidelines. For example, rules may require that all production casing, the steel pipe that helps separate the oil and gas production from the exterior rock, be remove. Also, the well must be plugged 50 feet below the bottom of the well production area, the perforation and 50 feet above the perforation and the interval between (see the accompanying figure). Additional plugs and cement are required that isolate and protect the following:
- All freshwater zones
- All potential future commercial production zones
- Prevent in perpetuity leaks from or into the well
Because oil and gas production has been active since the 1859 Drake well in Pennsylvania, considered the beginning of the modern petroleum industry, many more wells have been drilled. For perspective, according to Fractrakcer Alliance, there are currently more than 1.6 million active oil and gas wells in the United States alone. In Kern County, California, there are over 77,000 active wells. Once these wells become uneconomic and older inactive wells yet to be P&A’ed plus new wells being drilled every day, the volume of wells needing to be plugged and abandoned will grow.