Evaluation of rock mechanical properties to assist hydraulic fracturing in a tight oil reservoir

Abstract

Horizontal wells intersecting multistage transverse hydraulic fractures are the key to the development of tight sandstone oil reservoirs. A major challenge in hydraulically fracturing tight formations lies in relating the design to the rock properties, so that a predictive model can be constructed to guide fracturing design. Tight sandstones usually contain natural fractures, and heterogeneity of the rocks leads to a varying brittleness index in different areas. These rock characteristics have a strong impact on the effect of volume fracturing. Here, we propose an approach to understanding fracturing geological characteristics and to analyse the impact of geological parameters on fracture. Using the Chang 7 reservoir in the Heshui area of the Ordos Basin as an example, we present a method for evaluating rock mechanical properties and correlate the evaluation with fracturing design. The results provide a theoretical basis for adaptability analysis and a guide for future fracturing design in the Ordos Basin.