Thickness Measurement of Fracture Fluid Gel Filter Cake after Static Build Up and Shear Erosion

Abstract

The hydraulic fracturing treatment is an essential tight sand gas reservoir stimulation that employs viscous fluid to break the formation rock to create a fracture and transport the propping agent to support the fracture from naturally healing. Despite proven economic benefit, the hydraulic fracture fluid damages the producing formation and the propped fracture. To analyze the gel damage effect quantitatively, the filter cake thickness is used as a parameter that has not been measured before. This project was divided into two stages. The first stage built up a filter cake and measured the filter cake thickness by a laser profilometer. A correlation between leakoff volume and filter cake thickness was produced. The second stage eroded the filter cake by flowing original fracturing fluid through the core sample to study the fracturing fluid shear clean up effect on filter cake thickness. The filter cake was built up in the lab and the thickness was measured with different methods. The profilometer has been tested as an effective tool to measure the filter cake thickness. A correlation for crosslinked guar fracture fluid filter cake thickness was produced. An experiment setup used to shear erode the filter cake was built and tested. The results showed the filter cake was not eroded at 200 s-1 shear rate.