Rong Lu

Nowadays hydraulic fracturing is becoming the most popular practice for low permeability reservoirs. While in some cases fractured wells show superior productivity than non-fractured wells, in other cases the effective fracture length which is used to channel gas and oil from reservoir to wellbore, is much shorter than the propped fracture length, thus leading to a lower-than-expected production rate. The main reason is the unsatisfactory well cleanup following the fracturing treatment. In this work the research is focused on capillary pressure’s role in post-fracturing well cleanup. Capillary pressure is inversely proportional to relative permeability to hydrocarbon fluids. Looking at the LaPlace-Young equation, capillary pressure is determined by interfacial tension, contact angle and pore throat radius. Each of the three components is examined first in respect to its role in well cleanup, after which methods of reducing capillary pressure are investigated. Methods of lowering interfacial tension, alteration of contact angle and controlling of effective pore radius are come up with.