Marco Polo Deepwater TLP

Abstract

This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper SPE 95331, "Marco Polo Deepwater TLP: Completion Implementation and Performance," by J. Burman, SPE, Exploitation Technologies LLC, and K. Renfro, SPE, and M. Conrad, SPE, Anadarko Petroleum, prepared for the 2005 SPE Annual Technical Conference and Exhibition, Dallas, 9–12 October. Novel well-completion techniques and exceptional field execution allowed the six well completions in the Marco Polo deep-water tension-leg-platform (TLP) project to be accomplished in world-class fashion. All six wells (17 frac packs) were placed on pro-duction in only 168 days, including 14 days lost because of storms. The full-length paper focuses on how the implementation challenges of completing 17 zones in six deepwater dry-tree wells with a 1,000-hp rig were met and highlights a number of concepts and technical firsts that can be used in other deepwater development projects. Background Field Development. The Marco Polo field in Green Canyon Block 608 in the Gulf of Mexico (GOM) was discovered in 2000. Six development wells were drilled in 2002 and 2003 and were temporarily abandoned to await completion of the TLP. The TLP hull and deck were installed in January 2004 and were designed to accommodate a 1,000-hp completion rig to run riser tiebacks and perform completions. Only 88 persons are allowed on the platform at a time because of U.S. Coast Guard rules, a significant issue for rig operations. Reservoir. Initial reservoir pressures and temperatures range from 6,700 to 7,600 psi and from 115 to 122°F, respectively. Reservoir fluids are undersaturated black oils, with gravity ranging from 30 to 34°API and gas/oil ratio ranging from 700 to 1,000 scf/STB. Completion-Design Overview. Multiple pay sands, low reservoir temperatures, the requirement to gas lift the wells, and the deepwater environment drove the design of the Marco Polo completions. After significant flow-assurance modeling and evaluation, dual-barrier risers with insulating gel and a separate gas lift string were chosen as the upper-completion design. The sandface-completion design focused on risk management during completion operations, with the hardware designed to minimize future intervention risk. The 17 pay intervals in the six wells were developed with multizone, selective single, stacked frac-pack completions, using sliding sleeves with a concentric isolation string for zonal isolation. Multiple chemical-injection points are installed for hydrate, paraffin, asphaltene, and scale prevention. The installation of fiber-optic technology for downhole-pressure and -temperature sensing assisted in well surveillance and hydrate prevention. Fig. 4 in the full-length paper shows a generalized Marco Polo wellbore schematic.