With the rapid increase in number of major development projects in soft sand reservoirs in the last 20 years the industry has had to develop a range of sand control completion technologies to deliver high rate, reliable wells to support the production and injection. Sand control completion systems for production wells are generally mature and are broadly speaking typically successful. The development of reliable sand control systems for water injections wells has however typically proven to be significantly more challenging and this has impaired the economics of multiple projects by either necessitating the installation of more water injection wells, the periodic remedial repair of existing injection wells or suffer the inevitable impact on production rates and reserves recovery.
In many locations Cased Hole Fracpack (CHFP) or Gravel Pack (GP) completions have proven to have the capability to deliver high rate water injection wells. However, their long term reliability is often compromised due to the loss of the annular pack proppant when injecting water above formation fracture pressure. The loss of the annular pack proppant compromises the sand control system and reduced injection rates and formation fill in the wellbore typically soon follow.
In order to address this issue of annular proppant pack loss, a project was initiated to develop and qualify a proppant system that would remain immobile in the casing to screen annulus of CHFP/GP completions over life of well even when injecting water at high rate (in excess of 30,000 bbl/day) above formation fracture pressure.
Potential solutions from both inside and outside the oil and gas industry were reviewed and put through a rigorous program of lab based screening tests. Successful products progressed to the second stage qualification process of further lab scale and larger yard scale testing.
The final phase of the qualification process involved taking the preferred proppant product, a new generation resin coated proppant activated by a combination of a chemical activator additive in the fracturing fluid and temperature, and performing two onshore field trial operations which included several months of high rate water injection. The first installations of the new proppant product in deep water injection wells are expected from 2016 onwards.
One of the main challenges in the program was how to demonstrate suitability for both the installation process and life of well down hole service conditions in the lab and yard environment in a short time frame. This demanded the development and construction of a wide range of novel test procedures and apparatus. The results of this qualification and testing program will be discussed in this paper.