LU Yan-qiu

 

(Shengli Oilfield Exploration and Development Research Institute, Dongying 257015, China)

 

Abstract：The high clay content and the expansion of clay mineral in heavy oil reservoir for the 1st Member Shahejie Formation in Jinjia Oilfield cause strong water sensitivity, which restrict the thermal recovery, so, the study on heat changing of clay mineral is crucial. Differential thermal and thermogravimetric analysis and experiments including the crystal axial range test, analysis of aqueous solutes, X-Ray Diffraction, SEM and oil-bearing thin section after the tests in high temperature in autoclave show that axial range and expansion of montmorillonite are huge during surface water removal from montmorillonite at 100－150 ℃, which is easy to plug the pore throat resulting in poor physical property, indicating the crude oil spillage and making high saturation of the residual oil; at 200－300 ℃, axial range and expansion of montmorillonite become small with B interlayer water off, and coupled with minerals corroded by high temperature, and pore throat connectivity is improved. Physical property of the reservoir becomes good, and the remaining oil saturation decreases because the crude oil overflow easily .

 

Keywords: strong water sensitivity; heat changing of clay mineral; heavy oil reservoir; Jinjia Oilfield; 1st Shahejie Formation

 

 

ACTA MINERALOGICA SINICA Vol. 36, No. 3, 2016, Page 359-364