Paper: A Discussion Of Cluster Perforating vs Limited Entry Completion Techniques

When an operator is faced with the prospect of fracture treating large pay intervals, several options exist. The most popular technique appears to be single stage limited entry, followed by multiple stages with bridge plugs or baffle rings. With the growing acceptance of 3-D fracture simulators the technique of cluster perforating has provided a third option. The 3-D models often suggest that large intervals can be effectively connected to the wellbore using a single propped fracture initiated from a relatively small perforated interval. This technique is often unpopular with operators who feel that each foot of net pay must be connected to the wellbore with a perforation. Perforating large intervals may lead to the creation of multiple fractures, though, especially when the wellbore or fracture is not vertical. . This can be counterproductive to maximizing fracture lengths, particularly when the design assumed- a single fracture. Field examples are provided to support the theory of multiple fractures and small interval perforating. A model is then presented to aid in the staging and perforation design process.