Investigation Andapplication Of Integration Approaches For Thief Zone Identification

Waterflood development is one of the most common secondary recovery methods andhas been widely used in most oil field. Although it does well in improving oil recovery,waterflooding development causes some damage to reservoir.Thief zones form easily in Long-termwaterflooding reservoirs because of fingering,which made the water reach oil wells soonwithout driving oil effectivly. Then the water cut of oil wells rises and the effct of waterflooddevelopment becomes poor. So it is very important for us to identify the existence andposition of the thief zones.A lot of literature survey shows that for the study of reservoir thief zone, predecessorshave done a lot of research work. They use different methods of thief zone identificationcalculation containing different kinds of materials, which formed a very rich and systematicresearch theory.First, the recognition methods of thief zone are classified and their mechanismis understood. Second, in the above various identification methods, Holzer curve method,improved moisture index characteristic curve method, grey relational analysis method,dynamic reservoir correlation method, fuzzy comprehensive evaluation method and hydraulicdetection technology are selected and their principles are studied deeply. Third, a softwarecontaining the six methods using VB language is made. The software interface is clear andsimply operated. It can calculate and compare the results to identify quickly adopting manykinds of recognition methods, which can effectively improve the accuracy of thief zonesrecognition and identify the existence and the position of thief zones between oil and waterwells. Last, the software is taken use of an oil field. The results are collected and analyzed.The existence and the trend of thief zones are got to know, which lays fundations for profilecontrol and water shutoff.