The Cement Packer: A Simple and Economic Method of Accessing Bypassed Reservoir Potential

Abstract

This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper SPE 108973, "Multitype Application of Cement Packer: Simple and Economic Method of Accessing Bypassed Reservoir Potential," by Muhammad Idris, SPE, Martin Rylance, SPE, and Krisjahbana Joenoes, Vico Indonesia, and Nanang Firmansyah and Anton Supriyono, Halliburton Indonesia, originally prepared for the 2007 SPE Asia Pacific Oil and Gas Conference and Exhibition, Jakarta, 30 October- 1 November. The paper has not been peer reviewed. Cement-packer operations offer a potentially attractive economic opportunity for a rigless intervention to add additional hydrocarbon potential to a well. The full-length paper details the steps involved in this operation. The cement-packer process was first introduced in 1995; since then, a number of variants of the approach have been developed and applied. These variants have been driven in response to individual-well limitations, special requirements, and increased technical understanding and experience. Introduction The Sanga Sanga Production Sharing Contract (PSC) fields are in the onshore part of the Mahakam delta, East Kalimantan, Indonesia. Vico Indonesia has been actively exploring and developing fields within the Sanga Sanga PSC since 1968. The initial exploration drilling phases resulted in the discovery of the giant Badak and Nilam fields. Over the next decade, additional commercial discoveries were made to the west, along the Sanga Sanga anticline—namely, the Semberah and Mutiara fields. The hydrocarbon accumulations are located in the Middle Miocene sequence of numerous distributary-channel sandstone reservoirs, with mixed structural and stratigraphic trapping mechanisms. A combination of a highly complex fluvial-deltaic environment and increasing field maturity has resulted in a significant challenge for ensuring a continuous development strategy for the remaining reserves while maintaining economic conditions to meet commercial requirements. Completion Philosophy The completion philosophy, within the Vico developments, has evolved over the years. In the early field developments, between 1970 and 1994, the philosophy was to use multiple strings. Typically, a well was drilled with a 12 1/4-in. hole through the F Sands and a 9 5/8-in.-casing string was run. Subsequently, an 8 1/2-in. hole was drilled across the deeper G Sands, and a 7-in. liner was run to total depth. The wells then were completed with two separate produc-tion strings and selective completions (Fig. 1). The tubing strings were either both 3 1/2-in. or a combination of 3 1/2- and 2 3/8-in. strings. Only a single string would penetrate the 7-in. liner (referred to as the long string), with selective zones isolated between packers and behind sliding sleeves within the 7- and 9 5/8-in. sections, where the second string terminated (referred to as the short string).