First Three Thru-Tubing Sand Control Remedial Works Using Ceramic Screen in ACG Field: Design, Execution, Evaluation and Strategy for Next Jobs

Abstract

The Azeri-Chirag-Gunashli (ACG) is a giant field located in the Caspian Sea, Azerbaijan. The major reservoir zones are comprised of poorly sorted and weakly consolidated multi-layer sandstone formations. While Open-hole Gravel Pack (OHGP) completions have become the standard design for production wells, there are also several Cased & Perforated (C&P) wells from early field development along with some opportunistic Up-hole Re-completion (UHRC) C&P wells that were converted from OHGP. As the field matures with increasing depletion, water cut and gas/oil ratio (GOR), OHGP wells with vulnerability in the pack (incomplete pack) and C&P wells start to produce sand. Consequently, those wells are choked back resulting in sand-induced production deferral. Several sand control remedial work technologies were evaluated for the field and ceramic screen technology was chosen due to higher erosion resistance to cope with high flow rates and GOR in ACG wells. Three thru-tubing sand control remedial works using ceramic screen has been trialed successfully, both inside C&P well and high angle OHGP wells with unpacked section at the toe which previously isolated by bridge plug. The ceramic screen bottom-hole assembly (BHA) was deployed using coiled tubing with total BHA string length up to 178m. A snap type connector was used to minimize number of runs into each well, by allowing running string of multiple sections of ceramic screen and blank pipe in one trip. The ceramic screen installation inside C&P well demonstrated higher post-job skin compared to OHGP application, however having ceramic screen in the well allowed to produce with 3x higher drawdown at higher water cut up to ~40% with limited sand production and extend the well life considering typical C&P well failed with much smaller water cut. The ceramic screen installed in OHGP screen across unpacked section shows minimal skin change. In average there was ~2,500 bbls/day immediate incremental oil gain after each sand remediation work. This successful result demonstrates the viability of this remedial works to unlock production potential of producer wells and reduce sand-induced production deferrals in the field. This paper primarily discusses design, execution, result and learning from the first three thru-tubing sand control remedial work that was done in the ACG field.