Experimental Study on a new type of self-propping fracturing technology

摘要

Hydraulic fracturing technology, as an important stimulation technique for low permeability reservoirs, is widely used in oilfields. The effect of fracturing is closely related to the proppant carrying and the proppant-placement. While in field application, polymer gel is usually used to carry the proppant, which probably results in the difficulty of injection, the formation damage and other problems. As far as the proppant-placement is concerned, the mainstream view is the sand bank shape. The circulation channel of oil and gas is mainly composed of pores between the proppant particles, with seepage being the main flow pattern.However, a new type of self-propping fracturing technology is proposed in this paper without any solid proppant carried in the process of fracturing fluid injection. Because the fracturing fluid itself will transform into solid proppants when the fracturing fluid reaches the target reservoir under certain conditions, which produces sufficient strength to resist fracture closure stress. Moreover, two kinds of liquids will be injected simultaneously instead of only one in the injection process, and the proppant-placement is controlled by the flow pattern of two-phase liquids, which brings about the discontinuous and heterogeneous proppant-placement without sand bank shape, changing the flow pattern of oil and gas. (C) 2019 Elsevier Ltd. All rights reserved.