Published: 06/07/2011
Published: 06/07/2011
Unconsolidated formations and high-permeability reservoirs are susceptible to fines migration. The main contributing factors are high formation-fluid-velocity, wettability alteration, change in water salinity, and rock failure. Typically, the fines migration problem occurs in the near-wellbore vicinity due to high drawdown pressures. Depending on the severity, it can result in rapid productivity decline, erosion damage to downhole and/or surface hardware, and surface facility upsets.
A properly designed frac pack can mitigate the migration of fines if it is indeed a problem. However, as insurance there are some technologies currently used to address fines migration in frac packs. These technologies have some limitations such as only being designed to treat the fracture but not the near-wellbore vicinity, prone to causing long-term damage to proppant pack conductivity, and needing remedial work to clean up the proppant pack followed by retreatment.
In this paper, we will discuss the development of a new technique that effectively controls the migration of fines within both the formation surrounding the near-wellbore as well as the fracture area and does not affect proppant pack conductivity. We first detail the laboratory testing program followed to develop this technology including synthetic pack fines migration core flow evaluation, compatibility with frac-pack fluids, and proppant pack and formation damage. Thereafter, we discuss the field deployment process and complement with case histories. The laboratory results demonstrate that fines migration in the synthetic pack is drastically reduced with this new technique, that the technique is applicable up to 280 degF, and that it can be deployed in commonly used frac-pack fluids. Production results of treated frac-pack wells have met expectation and after a year no fines production has been reported.