A New Approach to Drilling Fluids Engineering in HPHT Environments

Drilling HPHT wells pose a big challenge in the oil and gas industry. Wells with a BHST and BHSP in excess of 300 deg. F and above 10,000 psi respectively are considered as HPHT wells. Conventional designs and test equipment fell short of addressing the inherent problems associated with these types of wells. A typical oil and gas field was studied and prognosed to be HPHT field at 500 deg. F BHST and above 10,000 psi BHSP. The field was investigated and a new approach to drilling fluids engineering was developed through experimental procedures, simulation studies, field application and computer modeling. Actual field data were obtained and used for qualitative and quantitative guide for the development of a software called HPHT Rheo-Analyzer. Experimental and field results indicated that the rheological properties were dependent on temperature, pressure and also on the interaction effect of HPHT. A multiple regression results from the software showed good agreement with the experimental and the field values with less than 1% deviation. The model therefore served as a proactive step for practical drilling experience and well planning for HPHT wells in the XYZ field.