Proppant flowback stopped with coiled-tubing intervention

Liquid-curable resin placed with a pressure pulsing tool alters proppant into a consolidated, highly permeable pack.

Stephen R. Ingram and Philip D. Nguyen, Halliburton; and Al Hood, XTO Energy, Inc.

This article discusses experimental and field case studies of a remedial treatment technique to eliminate fracture proppant production. This process uses a low-viscosity consolidating agent, which is placed into the propped fractures using a pressure-pulsing tool conveyed by conventional or coiled tubing. The treatment alters loosely packed proppant within the fractures and formation sand close to the wellbore, changing it into a cohesive, consolidated, highly permeable pack. The process’s efficiency makes remediation economically feasible for wells with marginal reserves.

Many fracture-stimulated wells are subjected to curtailed production rates because of sustained proppant flowback problems. In fact, many wells are shut in because they are uneconomical to produce at rates that are lowered by produced proppant covering perforations. Produced proppant often damages downhole pumps and surface equipment, and often results in costly downtime.

Low production rates directly affect the operator’s potential revenue. Frequent workovers for cleanup or sand removal also are factors in revenue losses from proppant flowback or sand infill. The problem will return unless a treatment can remediate the problem at its source.

Conventional treatments are usually inadequate without mechanically isolating the perforations and are usually too risky or too costly for low-return reservoir conditions.

Resin materials have also been applied to treat proppant flowback. However, a key problem has been the inability to uniformly place the resin into propped fractures over the entire perforated interval. This problem is amplified by variable permeability, perforation debris, formation damage in the near-wellbore region, and the resin material’s high viscosity. Using coiled tubing and a treatment fluid system placed precisely into propped fractures can turn marginal wells into excellent producers, and do so cost-effectively.