Water-swellable packer (WSP) is used rather than oil-swellable packer (OSP) for open-hole packer-sleeve (OHPS) fracturing and completion in China. In this paper, the two improved WSPs including hybrid external casing packer (ECP) and WSP with corrugated packing element are developed to solve the problem of tripping and deployment in irregular horizontal wellbore. The hybrid ECP combines mechanical-set packer with water-swellable packing element. The WSP with corrugated packing elements makes structure more compact than the traditional packer.

The two solutions were successfully evaluated by bench test. The former combines the feature of high-rating sealing performance, instant fracturing operation with swelling-assistant isolation. The latter has advantages of smaller size, high reliability and easy tripping over traditional WSP.

During OHPS multistage fracturing trial in Sulige gas field, the first five-stage operations are performed with hybrid ECPs and the last two-stage fracture diversion treatment are performed with new WSPs. The fracture diversion was carried out by injecting temporary plugging agents (TPA). The sealing effectiveness is fully validated by long-time ambient pressure differential during fracture diversion. It is shown from field operation that the new OHPS based on improved ECPs is able to meet the requirements of completion and stimulation in irregular horizontal wellbore for tight sandstone reservoirs.

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