Pesca Pubblicazione scientifica Cost-Effective Completion Design for Offshore Oil Wells in Nigeria FILONE TECNOLOGICO TEMA produzione e cattura RIASSUNTO SPE MembersAbstractOil companies have been forced to become more efficient and try new ideas to remain competitive in today's economic environment. This involves re-evaluating the cost effectiveness of tubing and downhole equipment designs and trying innovative ideas that have potential for significant cost savings.This paper tells how Mobil Producing Nigeria (MPN), operator of the Joint Venture between MPN and the Nigerian National Petroleum corporation (NNPC), reduced completion costs as a result of efficient tubing design. Tubing and thread design are discussed in detail and statistical tubing data is presented to show the need for thread standardization. Gravel pack and other downhole equipment designs are discussed in detail with case histories presented. Emphasis is placed on elimination of unnecessary downhole equipment and considerations for future fishing operations.This paper also discusses in detail innovative ideas that reduced workover and completion costs during the last 24 months. These include:1. A plugback completion design within the same reservoir that allowed the lower part of the interval to be isolated when cased hole logs were questionable.2. Innovative use of a joint of tubing to retrieve lost washpipe.3. A gravel packed open hole completion through a milled window in an inadvertently sidetracked hole. The milled window was the original completion interval prior to the workover.4. Innovative use of the cementing unit to free a stuck gravel pack crossover tool.IntroductionMobil Producing Nigeria operates 17 producing offshore oil fields on behalf of producing offshore oil fields on behalf of itself (with 40 percent working interest) and its Joint venture partner the Nigerian National petroleum Corporation (60 percent working interest).The producing fields are located 12 to 25 miles (19.3 - 40.2 km) offshore of the south eastern coast of Nigeria due south of Akwa Ibom State as shown in Figure 1. These fields produce from a total of 171 oil wells drilled from 37 platforms located in 50 - 165 ft (15.2 - 50.3 m) of water -Producing reservoir depths range from 4000 Producing reservoir depths range from 4000 - 8000 ft (1219 - 2438 m) subsea. Virgin reservoir pressures for producing - reservoirs yield a normal gradient of approximately 0.45 psi/ft (10.2 Kpa/m). The sand units are poorly consolidated with porosities ranging from 20 - 40 percent. percent. P. 617 DATA Data di pubblicazione: 04/04/2013 AUTORI MURPHY SS NWANKWO AS ENTE DI AFFERENZA MOBIL PRODUCING NIGERIA RIVISTA SPE Production Operations Symposium, 7-9 April, Oklahoma City, Oklahoma