Tangguh is a large gas producing development located in Bintuni Bay, in the Papua Barat province of Indonesia, some 3000 km east of Jakarta, the capital city of Indonesia. Gas production from the Vorwata Field and LNG export from the Tangguh LNG facility started in 2009. The field and the LNG facility are operated by BP.
The Vorwata development consists of 14 wells drilled from two normally unmanned platforms. The wells were predrilled prior to completion of the LNG plant and are completed as 7" monobores. They are perforated conventionally and are limited to 240 MMscfd each due to erosional considerations. Production from the field is currently 1.3 Bscfd; this rate being limited by the throughput capacity of the Tangguh LNG plant.
During the initial testing phase following completion and prior to start-up, the wells were limited by the infrastructure to a maximum rate of 100 MMscfd. Pressure transient analysis (PTA) of the data obtained during this test phase indicated that most of the wells had high mechanical skins. A reservoir preservation study showed that these high skins were caused by near wellbore damage and could theoretically be reduced by producing the wells at higher rates.
Following start-up and establishment of stable plateau production, a rigorous well clean up and maximum rate testing program was carried out. The wells were flowed at rates up to 240 MMscfd and pressure build up (PBU) tests were subsequently carried out to evaluate any improvement in reservoir deliverability. The analysis of the post maximum rate test PBU data showed that the skins were reduced on average by 40% in each well.