Problems Encountered In Drilling and Completing Deep Wells

Abstract

Abstract Problems encountered in drilling and completing wells to 15,000' and below are reviewed in this paper. Statistical trends in deep well drilling indicate that increasing numbers of such wells will be drilled each year. Problems associated with this activity are similar to those of past shallow drilling. However, these problems are more severe and much more expensive than those in the past. The role of a drilling coordinator, with regard to the development of sound, workable drilling plans, is discussed. A method of well planning is presented that, if used, will reduce the frequency of expensive problems in deep drilling. Many of the recurring problems involved in deep drilling are discussed, as are some of the more recent engineering solutions to these problems. This discussion centers not only on the drilling problems, but on some of the completion problems, but on some of the completion problems as well. One such problem involves problems as well. One such problem involves the attempted completion of wells drilled below depths where commercial production is extremely unlikely to be found. A means of avoiding this problem is also discussed. It is concluded that a great majority of such drilling and completion problems could be eliminated in most cases by better planning, and better trained on-site rig planning, and better trained on-site rig supervisors carrying out the previously agreed upon well plans. Introduction Statistical trends in the drilling of oil and gas wells in the United States indicate that the number of deep wells is increasing and that the yearly average depth of these wells is increasing. There are two primary reasons for these trends. The first reason is the fact that there are fewer good shallow prospects to be drilled, and secondly, a real energy crisis is fast approaching in the United States. To avoid this energy crisis problem, operators are spending vast quantities of monies to drill what we will call "deep wells". For the purpose of this paper, a "deep well" is defined as a well drilled below 15,000' for the purpose of exploring for and producing of oil and/or gas. The first such well was drilled in 1939, but the real increase in this activity started in the 1950's. The statistical trends for the yearly average well depth and number of wells drilled to at least 15,000' are shown in Figure 1.