Computer Applications in Oil Production: A Viewpoint

Abstract

Distinguished Author Series articles are general, descriptiverepresentations that summarize the state of the art in an area of technology bydescribing 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 presentspecific details only to illustrate the technology. Purpose: to informthe general readership of recent advances in various areas of petroleumengineering. Summary. This paper reviews selected areas of importance and indicates thegrowth directions of computer applications in oil production. The key messageis that alert petroleum engineers must make a concerted effort to keep abreastof computer applications in the field or else fall behind. Those who want tomake the effort may be interested in available software types of usefulapplications, and approaches for getting more involved. The paper also offerswords of caution on how to obtain proper use and avoid abuse. Introduction Surely we have all heard the statement that after 30 years of explosivegrowth the computer industry is still in its infancy. This statement was true10 years ago, and no doubt, we can expect even more exciting growth in the next10 years. What is going on is more than just rapid technological advances. Attitudinal changes are being thrust upon us. Ten years ago, many professionalsand managers were aware of the explosive computer growth but did not believethat they had to get involved personally. It was easier to back away fromdirect involvement 10 years ago, and many did so, perhaps because of unpleasantcomputer experiences, lack of interest, insecurity, or lack of conviction thatthe computer way was better. The attitude today is to get involved, althoughadmittedly in different ways. Because it is harder to resist involvement, newanxieties are created, such as a conflict between the desire to take advantageof what the computer has to offer and concern over potentially being blamed forcomputer mistakes, misuse, of lack of control. Even experienced users feelpressure. It is not practical to plan to "master the computer" and then sitback and rest on your laurels and feel secure. The rapid growth means thatcommitted computer users must feel the pressure to keep abreast. Some readerscould point out that they, as practicing engineers, have not seen many changesin their spheres of operation. All I can say is look around -- not only inpetroleum engineering, but in other engineering disciplines. Even if thepetroleum industry were not contributing willingly to computer change, it wouldbe dragged along by other branches of engineering. For instance, how can weignore the advances in graphics, e.g., computer-aided design, to assist inelectrical circuits or mechanical applications? Many readers can also point outthat they are already motivated to use computers. Many own or use a personalcomputer (PC) and have access to larger computers centrally located in theirorganizations. Members of this group may well be interested in obtaining adeeper understanding of available software, types of applications useful in oilproduction, and approaches for getting involved more fully. A thoroughdiscussion of these three topics is relevant but clearly beyond the scope ofthis paper. Selected examples follow of available software and applicationsthat have made an impact on me. The applications selected are in the areas ofplanning and analysis, rather than control. Key Software in Petroleum Engineering Reservoir Simulation. Reservoir simulation is another example of impressivedevelopments over the past 20 years. In fact, reservoir simulation has taken onan aura of its own because simulation is now within the reach of manypractitioners. Simulation is difficult to define because it is not a singletechnique, but an approach. The approach varies for different disciplines andtypes of problems. In our context, "simulation", means reservoir simulation, and it involves the use of mathematical equations (a model) or a computableprocedure to obtain some insights into the behavior of a reservoir. In short, the simulation approach helps us solve complex reservoir problems that cannotbe analyzed by other means, except perhaps by pure intuition. The basic flowequations for reservoir behavior were formulated clearly and elegantly manyyears ago; it is just that they are highly nonlinear and difficult to solve forreal reservoirs. This difficulty was overcome by transforming the nonlineardifferential equations into a set of finite-difference equations that, in turn, are more amenable to solutions. The successful approach has been to divide thereservoir into blocks, sometimes thousands, as shown in Fig. 1. Therelationship between the finite-difference representations and blocksubdivisions, as well as other aspects of simulation, are presented in manyarticles. JPT P. 143^