Publications

Tunu is a giant multilayer gas field located in the swamp environment in Mahakam delta, East Kalimantan. The field is divided in 2 zones: Main and Shallow Zone. The first zone located between 2,200 and 5,000 mSS, are consolidated sandstone and not prone for sand production. The latter, located between 600 and 2,200 mSS, are unconsolidated with strong aquifer support where downhole sand control is required. Started in 1990, field development focused only on Main Zone reservoirs considering the Shallow reservoirs ones were drilling hazard. Consequently all wells drilled are not completed with sand control, standard monobore or tubingless completion was chosen instead. As strong depletion of Main Zone reservoirs was observed, Shallow reservoirs then became potential targets to maintain field production. Development of Shallow reservoirs began in 2007. Since then more than 200 Shallow wells have been drilled, contributing to 50% of overall field production. Shallow reservoirs are badly consolidated hence sand will be produced along with the reservoir fluids. At early stage of field development, where biggest resources were targeted, Gravel Pack (GP) completion was chosen and considered as the most robust option to date. However as the condition of remaining shallow gas-bearing reservoirs are patchy with a bumpy structure and concomitant limited reserves, this hampered the justification to perform conventional GP. Finding other sand control techniques was deemed necessary to ensure continuous Shallow reservoirs development. Different sand control techniques, mechanical and chemical, have been implemented in Tunu field. Mechanical sand control techniques includes: GP, Stand Alone Screen (SAS), Ceramic Screen (CS), Cased Hole Stand Alone Shape-memory Polymer and Wireline Screen. While chemical technique implemented are: Sand Consolidation (SCON) and Sand Agglomeration. This paper will detail evolution of sand control techniques performed in Tunu field including innovative solution that allow us to develop low stakes Shallow reservoirs.