Multistage fracturing (MSF) technology becomes one of the main stimulation methods in horizontal wells. Despite the considerable experience, accumulated engineering knowledge and market appearance of a sufficient number of various MSF equipment manufacturers, operators are still rising the following questions while performing this type of well interventions: horizontal well length justification, number of MSF zones, distance between the ports, placement of open hole packers, recovering of frac balls etc. All of the above can be resolved to some extent with the help of traditional geophysics. However, production logging tool (PLT) performance in horizontal wells with MSF in most cases is limited by many complicating technological factors that reduce the possibility of successful surveillance. Most of the questions related to the surveillance of horizontal wells with MSF can be resolved using the technology of chemical markers integrated into a wide range of completion designs. This technology involves the installation of special polymer matrices with embedded intelligent chemical markers, either oil sensitive or water sensitive, into the completion hardware within the each zone of the MSF. When contacted by the target fluid (water or oil), the unique chemical signatures are released in very small concentrations and production from each reservoir compartment transports these unique signatures to the surface. Collection of the produced fluid samples at surface, analysis and interpretation, allows to resolve a wide range of conventional PLT tasks without conducting the PLT, including: the assessment of well clean-up, frac balls efficiency or sliding sleeves performance, quantification of the inflow per each zone monitored, detection of water breakthrough intervals and selection of zones for re-fracturing.
This article presents practical case studies of intelligent inflow indicators applications for monitoring the MSF wells.
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