Cut drilling costs without compromising performance

The target formation in central Oklahoma’s oil-rich STACK play contains high-temperature shales that swell on contact with conventional water-base drilling fluid, contributing to slower rate of penetration and frequent torque issues. To overcome the challenges of drilling long laterals through these reactive shale formations, area operators typically use oil-base mud. While oil-base mud provides wellbore stability and high ROP, it also contributes to higher disposal costs and health, safety, and environmental risks.

After using oil-base mud in previous wells, Continental Resources challenged M-I SWACO to provide a water-base fluid system that would meet drilling objectives in a 9,778-ft lateral with temperatures up to 300 degF and density up to 14.8 ppg.

Engineer a high-performance water-base mud

After performing intensive shale inhibition and lubricity testing on cuttings taken from offset wells, M-I SWACO recommended the HydraGlyde high-performance water-base drilling fluid system, which consists of the HydraSpeed ROP-enhancing primary lubricant, HydraHib shale inhibitor, and the HydraCap encapsulating additive. Hot roll dispersion lab testing and lubricity testing showed lubricity and shale inhibition comparable to oil-base mud.

To increase thermal stability, the M-I SWACO team engineered the HydraGlyde system using a base of 20-wt% sodium chloride brine and 2-lbm/bbl PTS-200 polymer temperature stabilizer.

Reduced drilling fluid costs by 40%

After the 9 5/8-in casing was set, Continental Resources used the HydraGlyde system to drill the entire 8 3/4-in section consisting of the vertical, curve, and lateral. The operator drilled the 12,932-ft interval with higher ROP and reduced drilling torque compared with the ROP and torque of a nearby well. In addition to improved operational performance, the HydraGlyde system mitigated environmental impact while contributing to higher cost savings. By eliminating the transportation, dilution, and disposal costs associated with oil-base mud, Continental Resources cut drilling fluid costs by 40%.