Tackling Gas Field Decline with Efficient Chemical Water Shut-off: Successful Application on Peciko Field (East Kalimantan, Indonesia)

Abstract

High water production in a gas well could significantly reduce gas production due to high friction losses in the tubing, the effect of water blocking in front of perforations and formation damage due to water, which, eventually, could lead to a significant loss of recoverable reserves. Selective mechanical water shut-off , (i.e. casing patch), the main technique used to solve this problem so far, has some disadvantages, mainly reducing the inside diameter of the production tubing which makes future mechanical water shut-off of the deeper reservoirs more difficult. Chemical water shut-off is the preferred solution to this problem.Peciko is a giant multilayer gas field located in the Mahakam delta of East Kalimantan, with water depths of around 30 -40 meters. There are more than 100 reservoirs per well, with average thicknesses of less than 1 m. Most of these reservoirs were perforated and produced commingled throughout the lifetime of a well. Efficient water shut-off is very critical when water breakthrough occurs at some of these reservoirs, in order to optimize gas production from the other reservoirs. Production logging measurements are used to identify the water producing reservoir to be isolated. This paper presents a successful field application of chemical water shut-off at Peciko field. In this application, the chemical water shut-off is the unique solution due to the thickness of the reservoir to be isolated (>8 m), not feasible using current mechanical techniques, and the interest of keeping a full bore access to allow future mechanical water shut-off for the other deeper reservoirs, while isolating the water source located above. Sealing quality at the isolated water zone was confirmed by a production logging job performed after the chemical water shut-off operation. This successful chemical water shut-off reduced the water production rate from 4,000 bwpd to less than 100 bwpd, and allowed an instantaneous gas production gain of 10 MMscfd with an estimated cumulative gain of 10 Bscf in 3 years. TX 75083-3836, U.S.A., fax +1-972-952-9435.

Comprehensive Review of Polymer and Polymer Gel Treatments for Natural Gas-Related Conformance Control

“…The PAtBA/PEI system was applied to control excess water production in a multilayer sandstone gas field located in Peciko offshore field, Indonesia (BHT = 150 °C, BHP = 2200) [ 10 ]. The treatment was designed for a monobore deviated well with multiple perforated layers.…”

“…The cement squeeze and epoxy resin are not preferable because of their poor injectivity, especially for treating matrix-related conformance problems and narrow fractures. In addition, it is challenging to clean the wellbore when the placement technique fails to reach the targeted depth [ 8 , 9 , 10 ].…”