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Coalbed methane (CBM) wells usually are dewatered with sucker rod or progressive cavity pumps to reduce wellbore water levels, although not without problems. This paper describes high-volume artificial-lift technology that incorporates specifically designed gas-lift methods to dewater Black Warrior CBM wells. Gas lift provides improved well maintenance and production optimization by the use of conventional wireline service methods.

Reeled tubing technology has proven to be beneficial in solving both economical and production problems in the Coal Bed Methane (CBM) industry of the Black Warrior Basin near Tuscaloosa, Alabama. The primary benefit from us i ng reeled tubi ng technology is one of economics. Operators can now prepare CBM well s for producti on qui cker than was previ ously possible.

Reliability of completion equipment and rig time are becoming more and more critical for subsea completions because of continually increasing water depths in which operators are being required to complete wells. In addition, completion designs must reflect the more stringent economic requirements of today's oil and gas industry. This paper will describe the use of a single-trip completion system that has been successfully and economically installed in the offshore Marimba and Bonito fields of South America. This new completion system has the capability to land the tubing hanger and install it in the wellhead before setting the packer and compensating for subsequent tubing movement. The new system also can employ pre-job calculations - based on initial well conditions and anticipated conditions during production - that help determine appropriate completion configurations and bottomhole equipment compatibility. Many failures in offshore wells, whether platform or subsea, can be attributed to inappropriate application of downhole completion tools or methods. Use of pre-job calculations during the equipment design stage can facilitate proper selection of design criteria and can help ensure operational safety and cost efficiency. The development of this new completion system will be discussed in detail. Three case histories that document successful test completions will be reviewed along with the economic gains and advantages that the reduction in rig time generated. Introduction Subsea completions were introduced to offshore operations in Brazil in 1977. Early "wet" installations were run in the Enchova field in water depths of approximately 400 feet [120 m] with production back to a floating production system. To date, 448 completions have been installed offshore and account for almost 60 percent of the country's production. Of these, 198 subsea completions have been installed in increased water depths. In 1985, discoveries were made in the giant deep-water Albacora, Marimba and Marlim fields at water depths ranging from 650 feet [200 m] to 6,500 feet [2,000 m]. There are indications that a new field exists south of Marlim at even greater water depths (Figure 1). History Subsea completions that were run in increased water depths during the late ‘70’s and early ‘80’s identified several problems. The traditional completion design called for a standard hydraulically-set retrievable packer, and movement compensation was accomplished through use of a tubing seal divider (TSD). A traditional subsea completion design is shown in Figure 2. P. 181^

This paper will demonstrate the use of reeled (coiled) tubing applied to gas lift technology and will add another method to the growing list of service and production capabi 1 it i es now fac il itated by ree 1 ed tubing. By using reeled tubing to install conventional gas lift valves, production enhancement of many wells is possible without workovers or change of exi st i ng tubul ars. This paper will discuss the design parameters, components and actual field results of using reeled tubing to install gas lift valves.