MWD Performance and Economic Benefits in the Zu Horizontal Drilling Program

Abstract

Abstract This paper describes the application of Measurement-While-Drilling (MWD) technology as used in a Horizontal Drainhole Drilling Program. The requirements of both formation evaluation and directional survey measurements while drilling will be discussed with reference to field results obtained. The ability of the MWD tool to make formation evaluation measurements, in order to identify casing seats and formation tops will be shown as essential to the project. The field examples described in this paper are from results obtained as part of the Atlantic Richfield Indonesia Inc. (ARII), 1986 ZU Field Development Drilling Program. The economic benefits of the utilization of MWD by ARII will be included. MWD proved to be ideally suited to the directional drilling of high angle wells, and horizontal wells in particular. The placement of horizontal completions was critical, and very little deviation from the proposed well plan could be tolerated. Lithologic interpretation was critical to prevent drilling out of the top or bottom of the pay zone and MWD was sufficiently reliable to track the horizontal section of the wellbore. Wireline logs were eventually eliminated on later operations. The overall economic benefits of MWD were derived by comparing surveying costs and drilling time costs between similar wells drilled and surveyed conventionally versus those drilled using MWD.