What is the optimal concentration or fluid combination to keep costs as low possible without sacrificing the effectiveness of completions and in turn production for each stage or perf cluster?
Swelling clay present in the unconventional reservoirs can potentially stifle the frac-length and effectiveness of completions. A reduction in drainage area or rapidly closing fractures can dramatically decrease the productivity of a given well. Understanding the bulk clay content or even the clay speciation of a given interval is informative, but actually testing them compatibility of fluids with different lithotypes encountered is the traditional method of determining fresh-water or treated drilling or completions fluids.
CST simulates the shear and chemical forces present in drilling and completions to measure the hydrating properties of shale. For this test, the mixing time and shale-solids content are held constant while the chemical characteristics such as pH are varied. Results can be graphed as fluid type versus time.
Download the full Capillary Suction Time datasheet.