Session: 11-10-02 Development of Unconventional Reservoirs-2

Paper Number: 79271

79271 - A Green and Environmentally Friendly Chelated Retarding Acid for Acidification of Sandstone Reservoirs 

Matrix acidizing is the main method to relieve formation damage in sandstone reservoirs. However, many problems in conventional mud acid acidification need to be carefully considered, such as fast acid rock reaction speed, short effective action time, excessive dissolution near the well zone, and the production of fluorosilicic acid, aluminosilicate, calcium fluoride and other pollution secondary sedimentation of the reservoir.

In this paper, a green and degradable amino acid chelating agent is synthesized, and a new type of sandstone chelating slow acid system is formed by using the characteristics of amino acid chelating metal ions, amino protonation and carboxyl ionization. The performance of this new type of chelating retarder acid was analyzed through experiments, mainly to investigate the chelating ability of chelating retarder acid to calcium and iron metal ions, the retarding performance of chelating retarder acid, corrosion performance, and acidizing flow effect and microscopic scanning electron microscopy analysis. The results show that the performance of the system is fantastic, which is mainly manifested by strong chelating ability to iron and calcium ions, low corrosion rate, good retarding performance. The permeability is increased by 225% after acidification. The results of electron microscopy scanning of the core surface before and after acidification show that the new acid solution acidification can effectively stabilize the movement of clay and particles, which is a good choice for sandstone acidification solution.

Presenting Author: Qing Wang China University of Petroleum (Beijing)

Authors:

Wei Liu ngineering Technology Research Institute of Xinjiang Oilfield Company
Qing Wang China University of Petroleum (Beijing)
Changfeng Xu Operation District of Hutubi Gas Storage of Xinjiang Oilfield Company
Mengchuan Zhang China University of Petroleum (Beijing)
Xinmin Kong Engineering Technology Research Institute of Xinjiang Oilfield Company
Erdong Yao China University of Petroleum (Beijing)
Que Junren Xinjiang Oilfield Company