Offshore Production Operations

Abstract

Distinguished Author Series articles are general, descriptive representations that summarize the state of the art in an area of technology by describing recent developments for readers who are not specialists in thetopics discussed. Written by individuals recognized as experts in the area, these articles provide key references to more definitive work and present specific details only to illustrate the technology. Purpose: to informthe general readership of recent advances in various areas of petroleum engineering. Summary Offshore production operations play a major and expanding role in the oilindustry. Compared with land operations, offshore operations typically requiremore planning because of the more complex systems, planning because of the morecomplex systems, equipment, and logistics involved. Higher completion rates andreserve bases are necessary to justify the high cost of developing offshorefields. Future exploration and development activity is trending toward deeperwater and more hostile environments, and innovative engineering and operatingtechniques will continue to be required to meet these challenges. Introduction The oil and gas industry began producing offshore in the late 1890's near Summerland, CA; wood wharves were built in the shallow ocean waters to supportderricks and necessary producing equipment. The industry has evolved andexpanded so that the number of offshore producing platforms now approaches 10,000 worldwide. Technology also has evolved for offshore production with specialized engineering and research in oceanography, platform construction anddesign, and production systems design. Today, offshore oil represents about 25% of the world's oil production. Themap in Fig. 1 shows the offshore basins in which industry is actively exploringand producing. It is evident that these offshore basins hold the key to future international oil supplies and that the petroleum industry must continue tomeet technological challenges in both established and frontier locations. Offshore production operations present a unique set of engineering andoperating problems compared with operations conducted on land. Developing fields offshore requires larger investments because of higher drilling and producing costs, transportation and logistical problems, and the need for aplatform base on which to conduct operations. For example, in 1983 the averageoffshore well drilled in the U.S. was twice as deep and four times as costly asthe average U.S. onshore well . Fields developed offshore, therefore, must becapable of producing at greater flow rates and in sufficient volumes to makethese significantly higher investments attractive. This paper provides anoverview of offshore production operations and keys on the major differences between offshore and land production operations, which include producing production operations, which include producing structures, well completions, production handling systems, operations organizations, and logistics. Offshore Structures The most obvious condition that sets offshore operations apart from those onland is the water itself. The offshore environment can range from shallow in land lakes and protected bays to deep, unprotected seas and oceans. Most operations offshore are conducted in water depths less than 300 ft [91 m];however, operations in water depths greater than 1,000 ft [305 m] now areoccurring frequently and will become more common with the advent of deep water technology. A platform must be constructed to support operations offshore, and special consideration is given to site-specific development and environmental conditions when designing the platform decks and structure. JPT P. 583