Chinese Journal of Applied Chemistry ›› 2024, Vol. 41 ›› Issue (9): 1271-1283.DOI: 10.19894/j.issn.1000-0518.240007

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Preparation and Performance of the Degradable Semi-Interpenetrating Network Temporary Plugging System

Xing-Chen LU1,2, Jian LIU1,2, Juan DU3(), Xiao-Rong GAO1,2, Yong XU2, Xiao-Qing REN2   

  1. 1.Sinopec Star Co. ,Ltd. ,Beijing 100083,China
    2.Sinopec Green Energy Geothermal Development Co. ,Ltd. ,Xiong 'an 071800,China
    3.Petroleum Engineering School,Southwest Petroleum University,Chengdu 610500,China
  • Received:2024-01-07 Accepted:2024-07-16 Published:2024-09-01 Online:2024-10-09
  • Contact: Juan DU
  • About author:dujuanswpu@163.com
  • Supported by:
    the Sinopec Star Co., Ltd. Science and Technology Project(FW2099-0047)

Abstract:

Heterogeneity is a fundamental characteristic of oil and gas reservoirs. The key measure improving the acidizing effect of heterogeneous reservoirs is diversion methods, which diverting agents are used to plug the high permeability layer and promote acid acting on the low permeability layer. In order to solve the problems of uncontrollable gelation time and serious damage of synthetic polymer diverting agents. A novel diverting agent SAXG with high strength and biodegradability was formed through semi-interpenetration using biomaterials sodium alginate (SA) and xanthan gum (XG). The optimal mass percentage of the system was optimized to 0.7% SA+0.3% XG with the goal of deformation and gelation time. The rheological properties and delayed gelation characteristics of this diverting agent were tested by rheometer; The degradability of the system was described with the content of residue; The difference between SAXG semi-interpenetrating network and SA gel was confirmed through scanning electron microscope(SEM); Finally, the core flow experiment was used to verify the divert acidizing effect of SAXG. The results showed that the gelation time range of SAXG is 14 to 456 min; The SAXG can be completely degraded in saline and acid solutions; The permeability of the core after diversion acidizing increased by 2.85 times compared to conventional acidification; The recovery rate of core permeability after degradation reached 98.6%. The SAXG can effectively promote the diversion of acid solution, thereby improving the effectiveness of acid stimulation.

Key words: Degradable, Semi-interpenetrating network, Temporary plugging system, Diversion, Acidizing

CLC Number: