Haynesville Operator Eliminates One String of Intermediate Casing, Saving $500,000 Per Well Using STAR SHIELD® Technology

During the last decade, operators in the Haynesville Formation of East Texas and Northeast Louisiana have experienced a substantial increase in water flows while drilling. This increase in saltwater flow is due to nearby saltwater disposal wells injecting into the mechanically weak formations above the Haynesville Formation. This flow is known to occur in the intermediate hole section and through the challenging Rodessa Formation. The extended mud weights needed to prevent this water influx exceed the fracture gradient of the mechanically weak Travis Peak and Cotton Valley formations below. Frequently, the common solution has been to run two intermediate casing strings. 

The operator sought to reduce total well cost and eliminate one intermediate casing string. Working with Impact Fluid Solutions, the operator used the latest Wellbore Shielding® Technology, STAR SHIELD® 100, together with STAR SHIELD®, to extend the mud weight window 1.5 lb/gal beyond the anticipated fracture gradient. Using this new fluid technology to drill through these weak formations enabled the operator to drill with the higher mud weight needed to prevent saltwater influx without incurring problems in the lower pressured formations below. STAR SHIELD 100 and STAR SHIELD were used at low concentrations (4 – 6 lb/bbl) beginning at 5,500-ft depth and maintained in the fluid system while drilling through the Travis Peak and Cotton Valley formations to the intermediate casing point, thus eliminating the need to run the extra string of intermediate casing.