Abstract

The Krisna Field, one of the eighteen fields currently operated in Maxus Southeast Sumatra's area of operations, has had an ongoing waterflood in the Lower Batu Raja carbonate reservoir since 1982. The reservoir was first produced in late 1980, but initial production decline and severe reservoir pressure drawdown created the requirement for a pressure maintenance program. Water injection was initiated in August 1982 with a one well pilot program which proved the feasibility of injecting unfiltered, chemically treated seawater. A fieldwide water injection project with five water injection wells was begun after the successful pilot program and a reservoir simulation study conducted by Lemigas.

A thorough field surveillance program provided information to affect changes in equipment selection and well configurations that has led to the efficient and successful operation of the waterflood.

This paper reviews the development and operation of the Krisna Lower Batu Raja reservoir and describes techniques used to improve recovery and enhance the operation of the waterflood.