Reservoirs in the Tarim Basin located in Western China can exceed 6100m (20,000 feet) TVD and often classified as high pressure high temperature (HPHT). These sandstone formations are ultra-deep with presence of natural fractures and temperatures approaching 190 degree Celsius (375 degree Fahrenheit) and reservoir pressure ranging between 110 to 125 MPa (16,000 to 18,000 psi). The development of such resources comes with unique challenges that require a coordinated and integrated approach when drilling, collecting sub-surface data, well completions, and intervention operations. All of these tasks pose unique challenges that are often not encountered in other hydrocarbon basins.

Hydraulic fracturing is a critical component to the well completion practice and is obligatory in order to maximize well productivity. This type of reservoir poses serious technical challenges that must overcome and account for the geological, geomechanical, and petrophysical interpretation. The integrated approach towards understanding the reservoir combined with the use of a novel fracture diversion technology was undertaken to ensure the maximum surface area contacted by the fracture with the reservoir and wellbore. The hydraulic fracturing design process involved the identification of intervals for multiple perforation clusters across the 200m (650 feet) reservoir section and then executing multiple stage stimulation treatments in which a fluid and proppant schedule would be pumped followed by the application of this dynamic diversion technology.

This paper will discuss this case history from a workflow perspective, introduction of this fracturing technology while using a weighted fracturing fluid with a specific gravity of 1.3, the treatment observations identified through real time microseismic, and discuss how the better reservoir understanding enabled an improved completion strategy. The eight wells with this approach are best in class from a production standpoint when compared to the three tier reservoir potential ranking approach. Finally, the lessons learned from the first phase of this project will help guide future development activities.