The Research On Logging Geosteering Of Drilling Horizontal Well

With the development of petroleum industry horizontal well drilling technique, as one of the effective method of improving individual-well producing rate , has obtained more and more extensive application in the world . Research and application logging geosteering technique of horizontal well drilling has been a very important project technique for successful drilling horizontal well.This study made a conclusion , namely , in order to realize geosteering , on the basis of making a better geological and drilling designation for horizontal well , we must make full use of MWD,LWD and integrate logging to identify lithology in real time, to interpret the LWD data and evaluate formation , to set up geological mode of target formation , to choose geosteering marked formation and compare simulative curves with LWD curves, to determine the drilling direction of bit upper and declination and the position in target oil-gas layer, to revise borehole track in real time, to make it extend in reservoir better interval as possible.Lithology identifying in real time can apply reliable lithology foundation for logging geosteering . In terms of well logging-facy identifying, based on curve automatic classifying and reading, we can extract some reflecting lithology parameter from the information of LWD to establish logfacy-lithfacy pattern and adopt gray conjunction method to recognize the rock type of drilling geological profile in real time.During drilling horizontal well, in order to follow and revise borehole track in real time, we must exact logging and geological pattern characteristic of target oil-gas formation and geosteering mark formation from information of offset straight well as reference pattern ,and create predicting mode of geosteering pattern to build simulative curve , and judge whether the bit has drilled the geological target oil-gas formation.Based on the study above, a software system of logging geosteering ofdrilling horizontal well is developed for MoBei oilfield in Xin Jiang . The system has provided some reasonable geosteering project and successfully steered drilling while it was applied to the process of drilling three horizontal well of MoBei oilfeild . Moreover, the oil output in each horizontal well increases by more than twice. All achieved the expectation aim and obtained remarkable economical benefit.