New lab test finds shut-in time to prevent proppant flow back

By OGJ editors
HOUSTON, June 2 -- Saudi Aramco has developed a laboratory test for determining the downhole curing time needed for preventing resin-coated proppant flow back.

During hydraulic fracturing, the large volume of cold injection fluid decreases reservoir temperature, but the resin coating on the proppant requires a certain temperature to fuse the proppant particles together. To ensure the right temperature for curing the proppant, the well must be shut in to let the reservoir temperature increase.

Aramco said prior to its lab method, the industry did not have a way for determining this curing time.

To find the optimum curing time, its lab method uses sound to test the proppant properties under constant downhole pressure and increasing temperature.

The company notes that its field engineers have adopted the method and have successfully prevented losses due to proppant flow back.

On May 11, Aramco received US Patent 7,712,525 for “Determination of Well Shut-in Time for Curing Resin Coated Proppant Particles,” developed by Hazim Abass, Mohamed Alqam, Mirajuddin Khan, and Abdulrahman Mulhem of the company's EXPEC Advanced Research Center.