Patent Number: 9,970,279

Title: Apparatus and methods for inhibiting a screen-out condition in a subterranean well fracturing operation

Abstract: A subterranean well fracturing system comprises a downhole well string having installed therein initially closed upstream and downstream sliding sleeve valve assemblies each openable to provide fracing fluid discharge outlets through well string side ports to an associated subterranean fracing zone. To inhibit an undesirable screen-out condition during formation fracturing, specially designed apparatus and methods are operative to sequentially (1) block the downstream valve seat, (2) open the blocked downstream valve seat using pressurized fracing fluid, (3) partially block the upstream valve seat, (4) open the partially blocked upstream valve seat using pressurized fracing fluid, a portion of which is flowed through the partially blocked upstream valve seat, and then (5) unblock the partially blocked upstream valve seat to permit a full flow of pressurized fracing fluid therethrough. In this manner, pressurized fracing fluid is simultaneously delivered to two fracing zones to inhibit a screen-out condition in the well string.

Inventors: Naedler; Mark Henry (Cypress, TX)

Assignee: UTEX Industries, Inc.

International Classification: E21B 34/14 (20060101); E21B 43/267 (20060101)

Expiration Date: 2022-05-15 0:00:00