Production Report

A concise guide to water frac design

Previously, water frac design was more art than science. Here’s a design procedure from a field operation standpoint, with field results for comparisons

 Bill Grieser and Jimmie Hobbs, Halliburton; Jeff Hunter and Jerry Ables, Devon Energy Corp.

 The popularity of water fracs has increased in recent years. A reduction in fluid cost and overall fracture-stimulation cost has in some cases revived development in low-permeability reservoirs like the Barnett shale in north-central Texas. Water fracs have also been used effectively in low-permeability reservoirs with large net pays, requiring large fluid volumes to attain adequate fracture half-lengths for commercial production.

 In most cases, water fracs pump some proppant. The amount and concentration is generally low compared to conventional fracture treatments. Water frac designs are not easily modeled with respect to fracture geometry, conductivity and proppant transport. However, the benefits of water fracs combined with good design methods can outweigh these problems. A design procedure is discussed herein for water fracs for field operations, including volume and rate requirements for specific fracture parameters. Comparisons are then made to field results.