STAR SHIELD® Product Line Reduced Mud Losses by over 90% in the Eaglebine Formation in Texas

An operator experienced severe lost circulation while drilling through several troublesome formations in Walker County, Texas. These formations include: Wilcox, Midway, Woodbine, Austin Chalk and Buda. The operator lost over 12,000 barrels of oil-based mud (OBM) on an offset well and experienced costly non-productive time (NPT). Controlling the losses with conventional lost circulation material, squeeze pills and other techniques were ineffective and resulted in subsequent wellbore instability.

On the next well, which was a direct offset, the operator applied a preventative and proactive approach. This operator has a long history of utilizing Impact’s STAR SHIELD® Wellbore Shielding® technology and realized they were encountering varying wellbore instability culprits, ranging from pre-existing natural fractures to mud weight induced lost circulation by significant formation depletion. To address the broad range of wellbore instability, the operator took a preventative approach to limit the following issues:

• „Mud weight induced lost circulation
• „Shale instability
• „Differential sticking
• „Whole mud losses to pre-existing microfractures that varied in sizes greater than 250-micron fracture width and less than 3000-micron fracture width

The operator treated the entire active circulating system with 5 lb/bbl of STAR SHIELD and 5 lb/bbl of STAR SHIELD 500 for preventative management. Next, they prepared and made ready at all times a 40 bbl, 40 lb/bbl STAR SHIELD 3000 pill to quickly pump and seal any pre-existing fractures greater than 500 microns. Realizing that a critical means of dealing with large, pre-existing fractures requires operational awareness and readiness to promptly seal the fractures before the fracture tip has an opportunity to extend and establish connectivity with other fractures.