Manifold Production Enhancement through Effective Horizontal Well Placement within a thin Heterogeneous Silty-Sands Reservoir: A Successful Case for the First Time in Wasna Field, India

Abstract

Prime objective of horizontal wells is to enhance production by maximizing reservoir contact. Hence it is extremely essential for deviated section to land accurately on top of pay horizon followed by optimum placement of horizontal section. Lateral formation heterogeneity in terms of thickness, lithology and stratigraphic pinching out makes proper horizontal well drilling through deltaic silty-sand reservoir in Wasna field, India; a real challenging job. Absence of Seismic data also adds structural dip uncertainty to the complexity of these targets. Real-time decisions making via optimal well placement technology are useful to drill these wells in a cost effective manner.In the studied field, several attempts were taken previously to drill horizontal well geometrically but the production result was never encouraging. Manifold production enhancement through accurate horizontal drilling has been achieved using conventional well placement method for the first time in this field. Well Placement workflow involves real time well trajectory designing while drilling based on layer earth model updation using LWD Image and Log data.The high resolution LWD images in real time have been instantaneously utilized to compute the orientation of the geological features across the borehole with high degree of accuracy. These computed orientations along with real time log data is used to update the near wellbore structural and stratigraphic model. Accurate configuration of subsurface layer earth architecture helped in effective forward designing of the well trajectory.This interactive 24X7 real time process finally enabled the successful horizontal well drilling within 1.5 m thick sweetest part of the reservoir. The well was placed with 95% NTG resulting around 5 times increment in initial production compared to the other existing horizontal well. This paper illustrates an extraordinary successful case study which opens new and exciting possibilities for horizontal well drilling campaign in the Western Onshore India. IntroductionIn many of the fields nowadays, horizontal drainholes, over vertical wells, are perceived as a better means of exploitation of the reservoir. But, boundary navigation and optimizing the drainhole within the desired target layer posses the biggest challenge in this regard.