Minimize Formation Damage in Water-Sensitive Montney Formation With Energized Fracturing Fluid

作者：Kong Bing^*; Wang Shuhua; Chen Shengnan

来源：SPE Reservoir Evaluation and Engineering, 2017, 20(3): 562-571.

DOI：10.2118/179019-pa

Slickwater has been widely used for hydraulic fracturing because it is inexpensive and able to carry proppants into the fracture (Schein 2005; Palisch et al. 2010). This fluid, however, is unsuitable for water-sensitive formations, such as the Montney formation. This is because water saturation around the fractures increases, and the clay swells when water leaks into the matrix, both of which hinder the flow of natural gas from the matrix into the fractures. N-2- or CO2-energized water-based fracturing fluids have been widely used in water-sensitive formations because they can minimize fluid leakoff during fracturing and help achieve higher-load fluid recovery during flowback (Burke and Nevison 2011; Barati and Liang 2014).
In this paper, multiphase numerical simulations are applied to study the formation-damage mitigation in the Montney tight reservoir with energized fracturing fluid. A simulation model is built and history-matched with flowback and early production data gathered from a typical Montney tight gas well. The behavior of the multiphase fluid leakoff and flowback is studied. Sensitivities of the foam quality of the fracturing fluid on the load fluid recovery are analyzed, as is the well productivity after stimulation. Statistical analysis to study the performance of energized fracturing in the water-sensitive Montney formation is conducted on the stimulation and production data of more than 5,000 Montney wells. We found that multiphase fracturing fluid has less dynamic fluid leakoff compared with that of a single-phase fracturing fluid (i.e., water). The major fluid leakoff occurs during the static leakoff period between the end of the stimulation processes and the start of the flowback. The gas phase penetrates deeper and faster into the reservoir matrix compared with the liquid phase, which contributes to the increased flowback volume of the fracturing fluid. Formation damage caused by fracturing-fluid leakoff can affect both early and long-term production. In addition, N-2 foam leads to the highest-load fluid recovery in the Montney formation, which is 1.6 times that of CO2 foam. This work provides critical insights into understanding the performance of using energized fracturing fluid to mitigate formation damage in tight formations.

• 出版日期2017-8