Volume 49

Experimental Investigation of Fracture Conductivity in Shales Considering Proppant Embedment and Crushing Huan Chen, Zhiming Wang, Pengyin Yan, Ying Yang

Abstract

Unconventional oil and gas resources, such as shale oil and gas, are gradually attracting great attention from all of the world. Horizontal drilling and large-scale hydraulic fracturing technology are used to efficiently extract oil from shale formation. A high long-term conductivity is essential for hydraulic fracturing, so accurate evaluation of propped fracture conductivity is of great significance for the development of shale reservoirs. In this paper, FCMS-V fracture conductivity system, scanning electron microscope and sieve analysis were used to study the influence of various factors on fracture conductivity, proppant crushing and embedment under reservoir conditions of the DG shale formation in Songliao basin. A visual study of proppant embedment into the shale rock was carried out. The effects of granule size, granulometric composition, concentration of proppants and closure pressure on fracture conductivity were revealed. It was found that due to the embedment of proppants, the long-term conductivity decreases by 10.2%. After exposure to a closure pressure of 30 MPa, the degree of crushing of the 30/50, 40/70 and 70/140 mesh proppants are 56.9, 38.8 and 26.7%. The findings from this experimental study could help hydraulic fracturing design for long term production of shale reservoirs.

Keywords shale oil, fracture conductivity, proppant embedment, proppant crushing