Field Optimisation of Acid Concentration of Visco Elastic Based Acid Using Fiber Optic Enabled Coiled Tubing (FOECT)

Abstract

Abstract Success of matrix stimulation treatments depend on the uniform distribution of treating fluids over the entire production/injection interval. Thus, when acid is pumped into a well, it naturally flows to the most permeable/least damaged zone. To avoid improper placement of acid into one interval of a zone of different injectivities, diversion techniques can be applied. Diversion can be accomplished by either mechanical means or chemical means. Diverting chemicals are deposited over the perforations or the formation. When deposited, they form a layer with a lower permeability than the formation it is covering. This imposes an additional pressure drop needed to penetrate the cake will cause the fluid to divert to another part of the perforated interval. Eventually, uniform injection is accomplished across the whole interval. Different concentrations of diverting agents can be used to get the required diversion, but how to know if the diverter pumped is indeed diverting or not is a challenge. Bottom-hole pressure or temperature responses can be checked during the job to get an idea if diverter is working properly. Thus, Fiber Optic Enabled Coiled Tubing with Fiber Optic Enabled Bottom-hole Assembly(FOEBHA) with pressure and temperature sensors for real-time downhole measurements and Distributed Temperature Sensing (DTS) is the best solution available. This paper describes the use of different concentrations of diverter i.e. visco elastic diverting agent and the behavior responses of downhole parameters with their usage.