Case Study of First Successful Aqueous Based In-Situ Formation Consolidation Treatment in the Gialo Field, Libya

Abstract

Sand production is a major challenge for many oil and gas industry operators, especially with unconsolidated reservoirs with weak bonding between the sand grains that enter the wellbore. This can eventually lead to damage to production lines and erosion effects to other surface equipment along with well productivity when drawdown exceeds the critical drawdown pressure. Although several techniques are used globally to combat sand production, most are uneconomical when considering the risk versus reward and the overall effectiveness in controlling sand production. An aqueous-based resin consolidation technique was evaluated for application in this case after the mechanical properties of the formation and sanding behavior in the field were estimated to be in the acceptable range for this technique to be applied successfully. An injection test followed by the aqueous-based consolidation treatment was bullheaded into the sand-producing zone resulting in minimal rig up and equipment required to operate. Post-treatment, a curing period allowed the resin to consolidate the coated sand grains. Compared to conventional resin, which requires large volumes to coat the near-wellbore region, this treatment used only a small volume of active resin. This effectively coated and cured in the near-wellbore region, providing excellent consolidation strength allowing the well to produce without any sand particles under the same drawdown applied to offset wells in the field. A case study is presented in this paper illustrating an effective, cost-efficient, and proven sand control solution for the high potential reservoirs of Libya. This solution can help develop fields that previously suffered from impaired well productivity and required expensive formation sand handling and disposal. Such a solution restored oil production without any considerable effects on the relative permeability of the formation to hydrocarbon or water while maintaining sand consolidation without any further sand production problems.