Multistage Stimulation of Sidetrack Wellbores Utilizing Fiber-Enhanced Plugs Proves Efficient for Brown Oil Fields Development

Abstract

Abstract The effective alternative method of multi stage fracturing stimulation of horizontal section of sidetracks completed with cemented liner and utilization of abrasive perforating technique started to be implemented in West Siberia for Priobskoe and Prirazlomnoe oil fields. The goal was to analyze all associated risks, make clear statistics and adjust it for specific oil fields for further implementation on a massive scale. Abrasive perforating is done through coiled tubing (CT) special downhole perforator that creates holes inside casing and caverns in nearwellbore zone by pumping sand slurry down CT string. After perforation has been done and the well has been stimulated with fracturing treatment, fiber-enhanced proppant plug is placed in order to isolate treated intervals. Adding degradable fibers to proppant plugs helps to achieve successful and efficient isolation between stages, while conventional proppant plugs are non-applicable due to gravity effects that cause settling of proppant and resulting in non-uniform proppant distribution and poor isolation efficiency. Extensive campaign was conducted in 2015 at Priobskoe and Prirazlomnoe oil fields, located in Khanti-Mansijsk region. The main challenge during all operations was to perform a successful bridging of wide hydraulic fractures. Different approaches to get isolation were used and the most effective variant is narrowly described. Also spacing and number of perforating stations were identified as critical parameter. First operational and wells productivity results look very promising and the technique was proven as a best option of multistage stimulation in short and slim sidetrack wellbores. Such sidetracks have been shown as efficient method to improve hydrocarbons recovery from mature fields. A comprehensive review of trial campaign with utilization of special technique is presented. Slim sidetracks can be stimulated with several stages in reliable, efficient and economical manner. Technology can be utilized for other brown fields in the region and outside Russia.