Experimental Study on Dual Flooding of Low Permeability Heterogeneous Reservoir

Abstract

Jurassic low permeability reservoirs with permeability less than 50mD in Changqing oilfield have strong heterogeneity, Now it's the "double high" stage, so it is urgent to explore enhanced oil recovery technology. In this paper, polymer and binary flooding experiments were carried out in parallel with cores of 30mD, 120mD, 160mD and 300mD to study the adaptability of binary flooding for low permeability heterogeneous reservoirs. The experiments show that the selection of appropriate polymer molecular weight and proper viscosity for binary flooding in low permeability heterogeneous reservoirs can not only ensure injection, but also increase the injection pressure. Improve the diversion rate of higher and lower permeability reservoir, expand the sweep volume of lower reservoir, and improve the oil displacement efficiency of heterogeneous reservoir. If the permeability is less than 10mD, the dual system cannot be injected into the reservoir.The permeability level difference of the reservoir is more than 6. Before the dual flooding, it is necessary to carry out profile control and block large pore to ensure the dual flooding effect. After the polymer is produced in the higher permeability layer, the diversion rate of each small layer in parallel core basically returns to the water flooding value, and the subsequent water flooding effect is not obvious. Therefore, profile control should be carried out after the accumulation of dual flooding.

Copyright 2023, IFEDC Organizing Committee.

This paper was prepared for presentation at the 2023 International Field Exploration and Development Conference in Wuhan, China, 20–22 September 2023.

This paper was selected for presentation by the IFEDC Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper, as presented, have not been reviewed by the IFEDC Technical Team and are subject to correction by the author(s). The material does not necessarily reflect any position of the IFEDC Technical Committee its members. Papers presented at the Conference are subject to publication review by Professional Team of IFEDC Technical Committee. Electronic reproduction, distribution, or storage of any part of this paper for commercial purposes without the written consent of IFEDC Organizing Committee is prohibited. Permission to reproduce in print is restricted to an abstract of not more than 300 words; illustrations may not be copied. The abstract must contain conspicuous acknowledgment of IFEDC. Contact email: paper@ifedc.org.