Application Of Geo-Steering In Horizontal Well Drilling

As a new directional well drilling technology with high practicability,geological steering technology is widely used in horizontal well drilling.However,due to the technical level problems in China,the related fields such as logging while drilling tools and supporting software are at a relatively primary stage,and the geological guidance ability is limited.Moreover,with the fluctuation of oil price and the reduction of development investment,the cost and efficiency requirements of drilling construction have been greatly improved,and the demand for geological guidance system is more urgent.Based on this background,this paper is based on the development project of horizontal wells in Yanchang Oilfield,Firstly,the software architecture of Geological Guidance System is determined by analyzing its functional requirements;subsequently,the method of tracing and evaluating the target formation in the geological guidance work by making full use of the existing logging data without adding new logging projects is discussed;the methods of establishing pilot geological model and adjusting wellbore trajectory are also analyzed,in order to obtain more accurate leading geological model,in order to be able to use it as the basis of well trajectory adjustment scheme is efficient and feasible.The research shows that,give full play to the basic role of geosteering system under the existing conditions,is to include a variety of existing data,but not limited to the block structure data of adjacent wells data,drilling logging data,logging data and engineering data,the parameters of deep understanding and make full use of.Through collecting and processing the existing data,the establishment and revision of the pilot geological model,the extraction of various logging response characteristics of target and marker layers,the real-time lithologic identification of strata and the preliminary evaluation of formation hydrocarbon-bearing property are completed to determine the real location of the bit in the stratum,And predicts the formation changes that may occur during drilling.Then it is necessary to use various theoretical and empirical formulas to calculate the usable slope of drilling tools in corresponding formations,adjustment and optimization of wellbore trajectory within the permitted scope of construction capacity,so that it can be in the target formation is conducive to the later development of the extended position through.Through a series of methods mentioned above,on the basis of not adding additional field equipment,the average penetration rate of the target formation of the experimental well is more than 95% in the practical application of the geological steering system,Compared with other horizontal wells in the study area,the average drilling rate of 60-70% has been improved obviously,The ideal effect of geological guidance has been achieved,and the drilling efficiency is improved.