Real-Time Modeling-While-Drilling for Optimized Geosteering and Enhanced Horizontal Well Placement in Thin and Complex Reservoirs

Abstract

With the growing demand for hydrocarbons, enhanced horizontal well placement resulting from optimized geosteering is becoming increasingly important. Optimal geosteering is accomplished by selecting the proper combination of loggingwhile-drilling (LWD) and measurement-while-drilling (MWD) tools as data acquired from these tools are directly deployed for interpreting and monitoring the well. In fact, achieving maximum success in geosteering is only possible through realtime interpretation and modeling of MWD/LWD data while drilling. Additionally, real-time 3D model updates while drilling deliver maximum guidance and assistance in geosteering to the proper well position by predicting the geology ahead of the bit. As a result, well placement risk is reduced because the associated uncertainty is quantified.A meaningful modeling-while-drilling campaign is greatly dependent on three main factors:  uninterrupted real-time data transmission  use of appropriate software modeling  selecting adequate modeling techniques Log modeling and 3D geocellular property modeling-while-drilling are two widely used variants of modeling-whiledrilling. Log modeling generates a series of modeled log responses along the planned well path considering the offset well information. Whereas 3D geocellular property modeling-while-drilling is comprised of two steps i.e., fine layering and gridding (FLG) followed by property simulation and regular model updates with new real-time log and well pick information. Each of these techniques requires MWD/LWD data, well picks, and surface grid information as input and uses different algorithms to complete the modeling. But, to obtain effective results both the simplicity and the adequacy of the modeling technique play a very important role in the procedure.In this paper, examples from two complex and challenging wells are described in terms of the advantages and benefits of using log modeling and 3D geocellular property modeling-while-drilling. It is concluded that modeling-while-drilling is extremely useful in optimizing horizontal well paths, maximizing well productivity, and reducing rig lost time. In addition, it allows professionals from different disciplines, to work together in an integrated manner for improved well placement.