Research And Application Of Logging Interpretation Method While Drilling

With the development of worldwide petroleum industry, deviated holes, branch holes and horizontal wells are used to exploit oil reservoir which is smaller, thinner and worse. Logging while drilling(LWD) is used to evaluate and Geosteering drill in this kind of reservoir because of its characters.Firstly, interpretation method of LWD is researched .Logging interpretation While Drilling includes lithological interpretation, formation parameters interpretation and oil interpretation while drilling etc. Information of LWD should be disposed and standardized before LWD is interpreted. Parameters related to lithology of the formation are extracted from LWD to establish a logfacy-lithfacy statistical model. Then, the formation lithology can be identified in real time. Parameters can be interpreted through the method used in straight wells. After logging curves in horizontal wells are revised to true vertical depth, oil-bearing formation is evaluated through the comparison of wells combined with geological information .Logging While Drilling have great difference with ordinary cable logging especially in deviated holes and horizontal wells. Comparison of cable logging and LWD carried out in different time indicates characters of mud invasion. Logging interpretation of HW04 while drilling is carried out, which is accord with the practical geological situation.In the same time, application of LWD is reseached too. Geosteering drilling in horizontal well by logging is an important application of LWD. In order to geosteering, log-geology model of target formation should be built according to logging data and the interpreting result of wells nearby. Geosteering parametersmodel is created to build simulative curves. Compared these curves with logging curves, the position and drilling direction of the bit can be found combined with the concrete geological situation. Through adjusting well path timely, the bit can be kept in the best position of the target formation. Moreover, because pressure prediction is another important application of LWD , formation pressure prediction is researched which is base on LWD.Based on methods above , an applied program in Visual Basic is developed to interpret logging data and Geosteering in drilling horizontal wells .The program guides to evaluate the oil field in a complicated geological situation and drill in horizontal well while it is applied to the work of interpretation and geosteering in the research zone. Moreover, the oil output in each horizontal well increases by more than twice compared to the straight well in the research zone. All obtained perfect result.