of the production engineer, who must produce the well and rework it when 

 necessary, and the reservoir engineer, who has the hest information on formation 

 characteristics such as distribution of permeability and porosity. The bottom- 

 hole settings are indicated as divided into two classes : set-through and set-on-top, 

 with numerous subdivisions under each class. The points in favor of each class 

 are shown in Figure 38-2. 



The hole size is indicated as a matter for joint decision by the producing, 

 reservoir, and drilling people, because it involves factors concerning all. Having 

 reached this decision, drilling operations must begin to "deliver" a completion 

 meeting these specifications. As indicated in the next bracket, drilling personnel 

 are charged with decision on 12 items which are indicated by classification 

 numbers. These items are analyzed separately in charts numbered accordingly 

 that set forth factors involved in choosing the most satisfactory method of 

 formation evaluation (fig. 38-3), drilling-in (fig. 38-4), etc. These charts are 

 self-explanatory. Study of these factors results in a well-completion plan and 

 cost estimate that must be submitted to management for approval. As indicated, 

 this plan is weighed from a standpoint of cost vs. expected return and may be 

 approved or modified. After final approval, the well is drilled and completed 

 according to the plan, with such operating modifications as may be expedient 

 during the process. 



If completed as a commercial producer, an engineering follow-up is indicat- 

 ed by the next bracket. This work is carried out by two groups: mechanical 

 engineering to check the performance of the surface and subsurface mechanical 

 equipment chosen for the completion, and reservoir engineering to check the 

 productive performance of the well on the basis of reservoir information, pres- 

 sure-build-up tests, etc. This phase is a process of continuous observation of 

 equipment and well performance; and the information, as indicated by the 

 arrows, is fed back to selection of the type of completion to be used on subse- 

 quent wells in the field. Thus, the cycle of a continuous process of well- 

 completion selection is completed. 



Reproduced by permission from API Bull. D6: Selection and Evaluation of W ell-completion 

 Methods. 



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