Experimental Study on Particle-Based Temporary Plugging Material Selection and Diversion Law of Shale Gas Reservoirs in WY Area, Sichuan, China

Abstract

A temporary plugging agent is an effective tool for increasing production in old wells. By considering the temporary plugging materials used in the remote WY area, three concentrations and five ratios under different fracture widths were designed and optimized. Thus, the fracture diversion under true triaxial stress was studied. The results showed that when the fracture widths were 2.0, 4.0, and 6.0 mm, the corresponding optimal plugging scheme was that the concentrations of the temporary plugging agent were 12.0, 18.0, and 18.0 kg/m3 and the ratios of 20–70 mesh to 200–300 mesh temporary plugging agent were 4:1, 2:1 and 4:1, respectively. When maintaining the same horizontal stress, an increase in the axial stress was accompanied by an increase in the fracture pressure; the initial fractures almost propagated along the direction of the horizontal maximum principal stress, but the shapes of the turning fractures were different. When the axial stress was the same, an increase in the horizontal stress difference was accompanied by a decrease in the corresponding fracture pressure and a gradual decrease in the degree of fracture turning. This study provides a basis for numerical simulation and field application of temporary plugging fracturing at fracture ends.

Safety and efficacy of Yaobitong capsules for lumbar disc herniation: A multicenter, randomized, double-blinded, parallel, positive-controlled clinical trial

“…In this study, JYK was used as a positive control drug because it is a Chinese patented medicine widely used for cervical spondylosis and LDH, and its significant analgesic, anti-inflammatory and detumescence pharmacological effects are similar to YBT. 26,27 Yaobitong significantly decreased the ODI and VAS scores, which may demonstrate that it could improve low back and leg dysfunction and pain. In addition, the curative effect of YBT was better than that of JYK, particularly in the degree of pain, as well as in enhancing daily self-care ability, sitting, standing, and social life in general.…”

Temporary Plugging Agent Evaluation Technology and Its Applications in Shale Reservoirs in the Sichuan Basin

“…Xu, H.L. [15] studied the effect of the temporary plugging agent's concentration on the sealing pressure in fractures using a diversion device. Zhang, R. et al [16][17][18] used a true triaxial hydraulic fracturing physical model device to study the effects of stress difference, material dosage, and the completion method on fracture propagation patterns and morphology after temporary plugging shale fractures using materials such as fibers, fiber and particle combinations, and water-soluble temporary plugging agents.…”