Case History: Designing and Implementing Wireline Tractor Operations for Deepwater, Extended-Reach, Sand-Control Initial Completions and Interventions

Abstract

Wireline tractoring technology has set world and Gulf of Mexico records for several logging applications during the initial completion and intervention of two extended-reach, deepwater frac pack wells and one extended-reach, deepwater water-injection well. This paper reviews some of the challenges involved with conventional conveyance methods in extended-reach wells, describes the planning process for wireline tractoring operations, including prejob modeling, and summarizes the results of a project.The authors will also share the lessons learned and best practices implemented. Proper utilization of this technology has led to significant cost savings for the example project. Introduction The Petronius project, located 150 mi south of Mobile, Alabama in the Gulf of Mexico, is operated by Chevron Corporation, with Chevron Corporation and Marathon Oil Corporation having a 50% working interest in the project.The project was sanctioned in August 1996 after a compliant tower and subsea development options were evaluated.The compliant tower alternative was selected based on superior well intervention capability, less complex seawater injection system designs, lower investment, and future hub potential.The 2,001-ft tall Petronius compliant tower is set in 1,754 ft of water, and is the world's tallest free-standing structure. The Petronius project targeted two main reservoirs that were delineated by seven preplatform well penetrations.Once these two original pay sands were developed, sights were set on developing potential pay much further from the platform in deeper waters. The development of these distant zones required mechanical success in difficult world-record, extended-reach processes and, of course, success in finding pay. For the past 3 years, a successful program of world-record, extended-reach deep-water well development has been ongoing.To date, there are 7 wells in the program with horizontal displacements of 14,000 ft to over 25,000 ft.This far exceeds the ~11,000-ft true vertical depth (TVD) of these wells.Fig. 1 illustrates the magnitude of the directional profile of the most challenging of these seven wells (Well #3 in this paper). This is quite an accomplishment considering the unconsolidated deepwater environment.To date, the program includes two water-injection wells and five frac pack-producing wells.Future well plans include an additional extended-reach frac-pack completion and a sidetrack of an extended-reach water-injection well.

Deepwater Extended-Reach Sand-Control Completions and Interventions

“…The tractor is used to convey the tools past the long sail area of the well profile and is disengaged at the bottom of these wells. The details of the planning and execution of these three logging jobs, including the modeling efforts, have been published previously (Whiteley et al 2005).…”

“…Then the isolation pipe was perforated above the gravel-pack packer, allowing production of the upper zone. More details of this record-setting plugback with the prejob and post-job wireline modeling have been published (Whiteley et al 2005). …”