Abstract
Abstract
In proppant stimulation treatments, when high fluid leak-off and low fluid efficiency is encountered, typically the first measure taken in job redesign is to increase the PAD volume and pumping rate to mitigate fracture width reduction. These measures will adversely affect the job treatment cost and increase the water load on the formation. High fluid leak-off and low fluid efficiencies could be due to high permeability formation and/or presence of Natural Fractures (NF).
In an effort to prevent permanent formation or proppant pack damage, this paper discusses the use of self-degrading multiple particle sizes while pumping. When these particles were used, it allowed to successfully seal off the width near the fracture's tip, controlling excessive leak-off and improving proppant placement volume.
Permeability and NF could be identified during pre-frac injection tests; however, in some formations when diagnostic injection is conducted at lower rate, NF might not be easily identified and could be opened-up unexpectedly during main fracture treatment as long as the net pressure increases, leading into an uncontrolled leak-off, early flush or screen-out. A comprehensive well data analysis performed during design stage along with an effective diagnostic injection test before main treatment can identify low fluid efficiency. This paper presents results from extensive testing and application of self-degradable particulates as a leak-off material for the first time in the middle east.
The Novel approach of this method allowed for controlled stimulation operations with the opportunity of limiting the high leak-off. This would ultimately increase the chance of proppant placement and avoid screen-out scenarios.