Using proppant indentation coefficient in design of hydraulic fracturing treatment of oil source rocks

Abstract

The purpose of the study is the laboratory determination of proppant indentation coefficients depending on the geological composition of the oil source rocks and their application in the design of hydraulic fracturing treatment. The laboratory researches used the core material of oil-producing deposits of the Domanic formation. The indentation of prop pant was carried out on the CTM-100 compression testing machine, in order to eliminate the measurement error, the size of the cells was additionally specified using ADF U300P microscope with the operation capacity either in reflected light or reflected and transmitted light only. As a result, the geological features of the Domanic complex were confirmed: a large content of organic matter was traced on the core material, the bulk of the rock was composed of carbonates with frequent lithological layering. The indentation coefficient of 20/40 proppan were as following: 0.2–0.4 mm in limestones, 0.23–0.45 mm in clay limestones, 0.47 mm for organic matter. The indentation coefficients for 30/50 proppant were as follows: 0.1– 0.5 mm in limestones, 0.13–0.55 mm in clay limestones, 0.47 mm in organic matter. The use of the obtained coefficients in the design of hydraulic fracturing treatment allowed to specify the fixed width of the crack opening that will have a positive effect on the predicted starting well yield under subsequent modeling. The proppant indentation is in direct relationship to the composition of the oil-producing rocks. When using the proppant coefficients it is advisable to pay additional attention to the proppant tracking map. The use of laboratory studies with subsequent modeling in the hydraulic fracturing simulator allows more accurate understanding of the fixed geometry of the crack of the formation fracturing. Estimation of the crack opening width at the stage of hydraulic fracturing design makes it possible to adapt the parameters of formation treatment, which has a positive effect on the lifetime of the crack width as well as on the well yield.