Design Methodology for Swellable Elastomer Packers for Well Construction Operations

Abstract

Abstract Since the introduction of swellable technology to the oilfield in 2001, its acceptance has grown significantly, and the scope of applications has expanded accordingly. Most of its usage has been in applications in horizontal, multi-zone fracturing, and in combination with inflow control devices (ICDs) and screens during the completion phase of the wells. One application that is gaining interest globally is the use of swellable tools during the well construction phase. The main objective here has been to provide extra sealing capability in addition to that of the cement sheath to prevent a micro-annulus or a mud channel when the packers are cemented in. In certain cases, swellable elastomer packers (SEPs) are designed to provide a full redundant seal above the top of cement (TOC). There are several reasons why SEPs and cementing operations are a good fit; primarily, the application of the technology is simple to implement, and allows pipe movement during the cement job. One other advantage is the fact that no specialized personnel are required for packer installation. However, several implications to the use of SEPs in combination with a cement job must be considered: Packer design and impact on cement placement; the packer must not impact the cement placement, as the main objective of a cement job is to get the cement slurry placed properly. Impact of swelling rubber on cement matrix once the cement is in place, it is important to know whether the SEP will impact the hydration process (setting) of the cement, changing the properties of the set cement. Bonding at the cement/rubber interface; the bond at the cement/rubber interface must be confirmed. This paper discusses the issues above, and benefits that can be expected when SEPs are used during well construction. Two case histories will be presented to illustrate the use of SEPs during the well construction phase.