Influence of a rock mass geo-mechanical parameters on the efficiency of a formation hydraulic fracturing
The article presents the results of studying geo-mechanical characteristics influence of clastic productive formations of oil and gas fields located in the Western Ural on the effectiveness of a formation hydraulic fracturing. It is noted that no correlations showing the influence of such parameters as the injected proppant amount, effective net pay thickness, porosity and permeability on wells’ productivity index increase after conducting a formation hydraulic fracturing was found. This article presents the statistical dependences that link the elastic modulus and the Poisson ratio influence in the interval of a formation hydraulic fracturing on the increase of wells productivity factor after conducting a formation hydraulic fracturing. It is established that the highest values of wells productivity ratio prior a formation hydraulic fracturing to wells productivity after a formation hydraulic fracturing are characteristic of the wells where the interval of a formation hydraulic fracturing has low values of the Poisson ratio and relatively high values of the elastic modulus. The formation pressure presence in the dependences allows making a general conclusion: the highest increase of productivity indexes after conducting a formation hydraulic fracturing is provided by the productive formation intervals which, in case of equal value of elastic modulus and Bio coefficient, have the maximum values of effective horizontal stresses, acting in them. These conclusions are especially important when conducting a multizone hydraulic fracturing in horizontal wells because it would be possible to solve the problem of the ports placement for the formation hydraulic fracturing in a more substantiated way.