An Overview of Horizontal Well Completion Technology

Abstract

Abstract Highly deviated or horizontal wells have led to new thinking in the application of well completion and stimulation technology. Horizontal drilling technology has advanced rapidly over the past few yews. It is now common to be able to drill and control horizontal holes of greater than 1,000 ft. displacement. However, horizontal completion technology is still on a steep learning curve and many completion practices need to be refined to contribute to the economic success of a horizontal project. In addition, a better understanding of reservoir performance with horizontal completions will be needed. Proven completion techniques used in less deviated wells have not proved to be cost effective or, efficient in this new application. This paper addresses several of these problem areas by discussing the shortcomings of vertical well completion technology and offers solutions to horizontal applications. Specific completion areas discussed include production string isolation, influence of horizontal wellbore deviation, stimulation considerations, sand control and downhole production equipment. Case histories of three Bima Field wells, offshore Indonesia, are presented to illustrate various completion practices. Introduction Since the usual purpose to drill and complete horizontal wells is to enhance production, the completion program must match the production objectives. There are many circumstances which lead to the decision to drill horizontal wells and these must also be considered in the final completion design. These circumstances, almost all reservoir related, include : - Thin Reservoirs. The Productivity Index (PI) for a horizontal well reflects the increased area of contact of the well with the reservoir. Typically the PI for a horizontal well may be increased by a factor of 4 compared to a vertical well penetrating the same reservoir, although enhancement by a factor of 10 or more may be achievable in certain circumstances (Fig.1). - Vertical Permeability. The productivity obtained by drilling a horizontal well partially depends on the magnitude of the vertical permeability and the length of the drainhole. P. 335^