Fracture initiation and propagation method for high-rate hydraulic fracturing in source rock reservoirs

Sadykov A.M. sadykovam2@bnipi.rosneft.ru “RN-BashNIPIneft” LLC (“Rosneft” PJSC Group Company) Ufa
Khaziev A.M. “RN-BashNIPIneft” LLC (“Rosneft” PJSC Group Company) Ufa
Sypchenko S.E. “RN-BashNIPIneft” LLC (“Rosneft” PJSC Group Company) Ufa
Fazlutdinov V.I. “RN-BashNIPIneft” LLC (“Rosneft” PJSC Group Company) Ufa
Ishbulatov M.I. “RN-BashNIPIneft” LLC (“Rosneft” PJSC Group Company) Ufa
Gayazov A.A. “RN-BashNIPIneft” LLC (“Rosneft” PJSC Group Company) Ufa
Gallyamov I.F. “RN-BashNIPIneft” LLC (“Rosneft” PJSC Group Company) Ufa
DOI: 10.24412/2076-6785-2022-7-96-101

Abstract
The use of multistage hydraulic fracturing (MSHF) with Plug-n-Perf technology in horizontal wells (HW) has proven itself as one of the cost-effective ways to develop low-permeability reservoirs and source rocks abroad. During hydraulic fracturing, namely when reaching the planned flow rate, there may be problems with the initiation and development of a fracture in the near-wellbore zone, characterized by high wellhead and bottom-hole pressure due to high stresses, which can lead to failure to achieve the planned flow rate, an increase in the required pump power. This article provides examples of a stepwise increase in the injection flow rate, which provides lower values of the injection pressure at the beginning of work, contributing to the successful implementation of hydraulic fracturing in source rocks.
The method consists in a gradual step–by-step increase in the flow rate to the planned value (10–15 m3/min) in order to both replace the fluid in the borehole with a high gradient of friction pressure losses and limit the growth of net pressure in the fracture. The flow rate increases
by 0,5–1 m3/min at each stage and only when the surface/bottom-hole pressure gradient stabilizes or decreases, the transition to the next stage is made. This approach makes it possible to control the increase in pressure associated with both the initiation and development of the fracture, and with the achievement of high planned rate, at which friction pressure losses increase.
The approach of a gradual stepwise increase in the injection flow rate during hydraulic fracturing operations allows limiting the wellhead and bottom-hole pressure, reducing the risks of accidents due to exceeding the maximum allowable working pressure. The described method is recommended for further use, especially in the production of high-rate hydraulic fracturing with cluster perforation using Plug-n-Perf technology.

Materials and methods

•    flow rate control at the beginning of hydraulic fracturing treatment;
•    stepwise increase in hydraulic fracturing flow rate.


Keywords
hydraulic fracturing, high treating pressure, hydraulic fracturing injection rate, hydraulic fracturing wellhead pressure, bottomhole pressure during hydraulic fracturing, unconventional reservoirs, low-permeability reservoirs, source rocks, fracture initiation and development
Download article