Diesel-based RHELIANT* fluid a hit in Wyoming
The newly engineered RHELIANT* D diesel-based drilling fluid system recently completed a successful inaugural field trial in Wyoming, where it was used in an onshore application for the first time.
The operator had previously used a conventional VERSADRIL system to drill the intermediate and main sections of its development wells in the Pinedale Anticline field. Common challenges in the area are low penetration rates and water influx from the formations drilled. M-I SWACO proposed modifying the widely used RHELIANT offshore, synthetic-based flat rheology system for use in the land application.
The new RHELIANT D diesel oil-based fluid was designed in the Houston Product Development and Technical Services Laboratories to meet the operator’s requirements for a relaxed HTHP filtrate, low gel strengths and an emulsion that would better counteract possible water influxes.
A well was chosen for the field trial and 1,800 bbl of RHELIANT D fluid were produced in the Mableton, WY, liquid mud plant. The intermediate section was drilled to 7,427 ft with a treated gyp/water-mud and POLYPLUS* system sweeps. Afterwards, the operator made an openhole displacement to RHELIANT D fluid to drill the remainder of the 8 1⁄2-in. intermediate section to 8,826 ft, where the 7-in. casing was set and the 6-in. production section was drilled to 13,417 ft. No special care or equipment was required for the RHELIANT D system, which was utilized on the same rig with the same solids-control equipment as the earlier Versadril applications.
Throughout the drilling operations, the properties of the RHELIANT D fluid remained in the desired ranges, and the system exhibited very low maintenance and treatment requirements, according to Mario Bouguetta, technical services engineer.
