Исследование геомеханических свойств пород-коллекторов для уточнения дизайна гидроразрыва пласта

Abstract

Introduction. The oil and gas resources of Russia have been growing mainly with hard-to-recover reserves of old producing regions and deposits located in hard-to-reach regions with undeveloped infrastructure for the last quarter of a century. The difficult conditions for the development of such fields and the extraction of residual reserves of the “old” fields create problems in hydrocarbons production, the complex geological structure causes great difficulty.Since the geological structure peculiarities of the fields often increase the risks of rapid well production flooding, the urgent task is to reduce such risks during hydraulic fracturing, to maintain the cost at a profitable level, and to ensure environmentally friendly conditions. The article considers the possibility of reducing the risk of water inflow along a hydraulic fracture and increasing the correctness of the fracture development prediction in a water-prone direction, which should ensure sufficient technological efficiency of work. Purpose of research is the need to develop innovative techniques and updated approaches to hard-to-recover oil reserves development, new techniques to improve the quality and success of work while maintaining their profitability. Research methodology. A comprehensive analysis of the hydraulic fracturing actual results, the results of laboratory studies and subsequent field tests. Research results and discussion. Based on the conducted studies, a technique has been proposed that allows determining the hydraulic fracturing design which makes it possible to reduce the risks of arbitrary, uncontrolled fracture propagation. The conducted field tests confirmed the significance and reliability of the proposed methodology. Findings. The article presents the results of studies of the hydraulic fracturing process. An updated technique for predicting hydraulic fractures is proposed, considering the reservoir rocks geo-mechanics. Field tests were carried out, which showed the effectiveness of calculations using the new technique – fluid inflows with reduced water cut and increased oil production from the target reservoir were obtained, i.e. penetration of cracks into the aquifer is not allowed. It has been established that during hydraulic fracturing it is necessary to fix the fracture with no more than 5 tons of prop pant. It was determined that the pad volume should be reduced to 50% of the injected prop pant weight. It was found out that it is preferable to use a linear gel to reduce the height of the hydraulic fracture, as well as to assess the need to correct the model based on the test operations results. The results of the research can be used on deposits similar in geological and commercial characteristics to those studied.