WorldOil

Tailor-made casing withstands mildly sour environment at cost savings

In 2007, a Texas-based independent operator needed a 110-ksi pipe grade specifically designed for mild sour service in the company’s large-scale drilling program in Leon County, Texas. The challenge was to develop a 110-ksi product that would be suitable for wells with the potential to develop a mildly sour environment, but without incurring the high cost of going to a C110 or T95 product. A customized 110-ksi product grade was developed for this application, consistent with all industry requirements, and the operator began using the new pipe grade in 2007, resulting in major cost savings. The tubulars used in drilling and completing oil and gas wells not only constitute a major portion of the operator’s total well cost, but also are critical components in the successful completion of the well. Consequences from a failed casing string can range from additional costs for salvaging the well to total loss of the well, and possibly environmental damage.