Customized Non-Damaging Drilling Fluids to Address the Challenges for Heavy Oil Wells - Case History from Kuwait

Abstract

Nowadays the global market demand for Heavy Oil is increasing and Kuwait Oil Company has a plan to increase the production of heavy oil, which is part of a long-term plan set out by parent group Kuwait Petroleum Corp. Drilling heavy oil wells needs a lot of efforts and expertise to be economically developed and produced. Gauged holes are the key for the production techniques used in this field, where cement channeling and perforation effectiveness are the main concern. To achieve this, a specific drilling fluid design was necessary. Laboratory tests and extensive research were initiated to customize the drilling fluid parameters and wellbore hydraulics necessary to achieve the objectives. The drilling fluid design goal was to provide enhanced inhibition for the clay and to provide good lubricity with a low friction coefficient to ensure smooth drilling and tripping operations in a gauged hole profile. This paper is describing the fluid behavior and hydraulics were designed in high profile to remain completely in laminar flow while drilling to minimize washout occurrence and maximize hole cleaning at low circulation rates (140 – 150 GPM) without the use of regular sweeps. The customized drilling parameters and practices, in addition to the knowledge gained from the laboratory testing phase, were transferred to the field. This resulted in field proven successes with more than 200 perfectly gauge holes being drilled. Case history from one well in Kuwait field is included in the paper.