Multistage Horizontal Well Hydraulic Fracturing Stimulation Using Coiled Tubing to Produce Marginal Reserves from Brownfield:Case Histories and Lessons Learned

摘要

The Baharyia formation is a common reservoir in the Western Desert of Egypt.It is characterized as a heterogeneous reservoir with low sand quality.It is comprised of fine-grained sandstone,thin,laminated, sand-poor parasequences with shale interbeds.The heterogeneity and low permeability of the Upper Baharyia reservoirs are the primary challenges to maintaining economic well productivity. The interest in developing low permeability reservoirs stems from favorable economics attributed to advancements in horizontal well drilling and hydraulic fracturing technology,offering methods to increase production by increasing the contact area of the producing interval.Subsequently,it became apparent that wellbore contact alone was not always sufficient for providing production increases expected,thus requiring multistage hydraulic fracturing(MSHF)stimulation treatments to achieve production targets. Primary well production analysis revealed that the cumulative production from the horizontal well discussed was enhanced from 37 to 70%of recoverable reserve and the recovery factor was doubled.From a production analogy standpoint,these resulted in reduced drilling of three vertical wells and had direct economic benefits by reducing the installed artificial lift strings,related expensive artificial lift equipment repairs,and the number of necessary workovers. This paper takes a multidisciplinary approach to help understand productivity enhancement of low permeability reservoirs in the Western Desert of Egypt,through a detailed analysis of well performance and successful implementation of MSHF in horizontal wells to maximize drainage volume around the well.It is intended to serve as guidelines to help operators facing similar challenges.