Reservoir Evaluation and Development ›› 2021, Vol. 11 ›› Issue (2): 235-240.doi: 10.13809/j.cnki.cn32-1825/te.2021.02.014

• Shale Gas Development • Previous Articles     Next Articles

Gelling acid fracturing experiment in Maokou marl formation of Nanchuan area

XIA Haibang(),BAO Kai,WANG Rui,XIONG Wei   

  1. Sinopec East China Oil and Gas Company, Nanjing, Jiangsu 210011, China
  • Received:2020-09-30 Online:2021-04-26 Published:2021-04-30

Abstract:

The marl gas reservoir of the Permian Maokou Formation in the Nanchuan area is characterized by low porosity and low permeability, high carbonate content, irregular fracture development, poor connectivity and strong heterogeneity. The conventional acid fracturing technology used to transform the reservoir directly has the problems such as the rapid reaction of acid under the reservoir conditions, and limited dissolution distance. Based on the typical geological characteristics of the Maokou Formation in this area, experimental testing and evaluation of the gelling acid system has been selected. A gelling acid system with strong viscosity, good compatibility stability and degradability in the mode of “multistage alternating injection of acid fracturing+closed acidizing” is screened. The gelling acid system has been successfully applied in Well-DS1HF in Nanchuan area for the first time, and the stable production is 23.05×104 m3/d under the production system of 10 mm nozzle.The good results verify that the application of this technology in marl gas reservoirs is feasible. It has a good reference and application for the development of similar gas reservoirs in China.

Key words: gelling acid, marl, horizontal well, acid fracturing, Nanchuan area

CLC Number: 

  • TE357.2