A State-of-the-Art Approach to Unlock the Potential of Complex Sour Reservoirs in Southern Oman During Global Market Downturn

Abstract

Abstract Recent years and especially the coronavirus pandemic have been very challenging for the oil industry, resulting in a significant reduction in investment, forcing companies to review budgets and search for more efficient and economical technologies to achieve the target level of hydrocarbon production and revenue generation. In PDO, one of the most challenging fields is "AS", where extreme downhole conditions require a very well-engineered approach to become economical. This field has already seen some of the most advanced technology trials in PDO that are also covered in multiple SPE papers. Based on the new approaches and techniques that were successfully implemented on recently drilled wells, it was decided to review the older, previously fractured wells in the area and assess them for a refracturing opportunity. The main challenge in this project was that these older wells were previously hydraulically fractured in multiple target intervals, therefore both zonal isolation and successful placement of the new fracs were becoming the major concerns. As the planned coverage by the new fractures was to ensure no bypassed pay, the only applicable technology on the market was a pinpoint fracturing process, whereby the targeted placement is achieved through limited entry perforations and focused energy of the injected fluid. The subject pinpoint technology anticipates that the limited entry sandblasting perforation is created and then proppant laden fluid is pumped through a sandblasting nozzle which is part of either a coiled tubing (CT) or a jointed pipe (JP) Bottom Hole Assembly (BHA), and the backside (or the annulus of the injection path) is used to maintain the positive backpressure from the top. This technology allows for choosing a desirable order of target interval selection inside the well, unlike conventional plug and perf or a simplified multistage completion, where the treatments must be placed only in order from bottom to top. Another advantage of this approach is a faster frac cycle through the elimination of wellbore cleanout requirement. Being a unique and first-ever application in the Middle East, using CT for placing frac treatments through a jetting nozzle demonstrates the full scale potential of this approach not only in conventional wells but also in complex, sour and High Pressure (HP) environments that are often found in the Sultanate of Oman and in the Middle East. This paper will cover the advantages and disadvantages, complexity and requirements, opportunities and lessons learnt in relation to this approach.