The "Spanish Bay" well was drilled from a production platform located offshore California in 1,075 ft of water. This record setting extended reach well overcame numerous technical and operational challenges and reached a total depth of 33,435-ft measured depth (MD) / 7,663-ft true vertical depth (TVD) with 29,720-ft displacement. This paper will highlight the rig package limitations and upgrades, describe key technical and operational challenges, discuss how the challenges were addressed, and describe key / unique operations.
A case history is presented describing the technical and operational challenges successfully overcome including limited hydraulics, high torque, pipe racking constraints, mud handling capacity, offshore logistics, and platform space limitations. As predicted by detailed torque and drag modeling, the well's 86º tangent angle required that drillpipe and casing be rotated into the hole to overcome the effects of negative weight. The 22,131-ft 9" × 10¾-in. intermediate liner was successfully floated and rotated to 29,831ft MD / 5,525 ft TVD. The well established a new North American extended reach drilling (ERD) record and a new global ERD record from an offshore location.
Introduction
Extended reach drilling refers to the practice of directionally drilling to geologic objectives located a significant distance horizontally from the drilling rig. The design and successful drilling of ERD wells require significant detailed analysis and thorough understanding of rig operating capabilities. Operators often design and build custom rigs or perform significant upgrades to existing rigs to meet the specific technical requirements for their ERD applications (McDermott 2005).
Some selected upgrades were required to drill the "Spanish Bay" well, but mostly existing equipment was used. Offshore logistics and space limitations on the producing platform were also factors in the effort to achieve the objectives of this ERD well. The techniques utilized to drill this well can be used on future wells, thereby extending the reach of existing drilling packages, minimizing capital investments, producing from previously out of reach areas, and improving overall project economics.
Field and Area Overview
The Santa Ynez Unit (SYU) is located approximately 20 miles west of Santa Barbara, California. Operations in the SYU area comprise an oil and gas processing plant in Las Flores Canyon and three offshore platforms located in federal waters in the Santa Barbara Channel. The three production platforms (Hondo, Harmony, and Heritage) range from five to nine miles offshore, and lie in water depths of 842, 1,200, and 1,075 ft, respectively. Each platform has a company-owned drilling package installed. The oil and gas produced offshore is transported via subsea pipelines to the company's processing plant in Las Flores Canyon. These fields produce low-gravity 12 to 20º API sour crude primarily from the highly-fractured chert reservoir in the Monterey formation.