Deepwater Extended-Reach Sand-Control Completions and Interventions

Abstract

Extended-reach, naturally perforated, water-injection, frac-pack producing completions and frac-pack producing selective completion interventions were successfully implemented in the deepwater Gulf of Mexico Petronius field, setting both Gulf of Mexico and world records. Success was achieved through careful planning of procedures and specification of equipment. This paper describes the planning for these challenging extended-reach completion and intervention operations, along with the lessons learned while implementing these case-history jobs. IntroductionChevron and Marathon each have a 50% working interest in the Petronius project, which is operated by Chevron. The field is located in the Gulf of Mexico, 150 miles south of Mobile, Alabama. The project was sanctioned in August of 1996 after both compliant-tower and subsea-development options were evaluated. The compliant-tower alternative was selected because of its greater well-intervention capability, less-complex seawater-injectionsystem design, lower investment requirements, 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 originally targeted two main reservoirs which were delineated by seven preplatform-well penetrations. Once these two original pay sands were developed, the operators set their sights on developing suspected pay zones much farther from the platform in deeper water. The development of these distant zones required mechanical success in implementing difficult world-record extended-reach processes and, of course, success in finding economic quantities of pay.For the past 3 years, a successful program of just such worldrecord extended-reach development has been ongoing. The program has seven wells to date, with horizontal displacements ranging from 14,000 to more than 25,000 ft. These horizontaldisplacement values far exceed the ≈11,000-ft true vertical depth (TVD) of these wells. Fig. 1 summarizes the directional data for the Petronius extended-reach program in chronological order of well development, and Fig. 2 illustrates the complexity of the directional profile of the most challenging of these wells.This extended-reach program is quite an accomplishment considering the unconsolidated deepwater environment. To date, the program includes two water-injection wells and five frac-pack producing wells. Three of the five producing wells include stackedfrac-pack completions. Future well plans include an additional extended-reach frac-pack producing completion and a sidetrack of an extended-reach water-injection well.

Determination of Insitu Reservoir Absolute Permeability Under Multiphase Flow Conditions Using Transient Well Testing

“…The Petronius Field is an oil field located in the United States Gulf of Mexico, approximately 120 miles southeast of New Orleans, Louisiana, and 100 miles south of Mobile, Alabama, under 1,750 feet of water (Pourciau 2007). The field produces from five zones.…”

Frac Packing: Best Practices and Lessons Learned From More Than 600 Operations

“…An internal abrasion-resistant drillpipe coating maximizes pump rates while eliminating internal buildup of pipe scale, pipe failures, and the need for pickling pipe (Pourciau 2007).…”

“…Applying high-viscosity gel slugs with high-density completion fluid regularly sweeps the well system. The work string should be rotated and reciprocated (Pourciau 2007) when such slugs are circulated, especially for a highly deviated or horizontal well. The debris is usually cleaned out of the well with a special tool (Hern 2010) (i.e., downhole casing scraper, downhole debris filter, downhole magnetic tool, or junk basket).…”