Overview of environmental protection methods in heavy oil cold production

Jian Sun, Yi Pan, Xia Bao, and Zhangxin Chen


Cold heavy oil production with sand (CHOPS) is a non-thermal method used in primary recovery. It improves heavy oil recovery rates by aggressively producing sand to form regions of increased permeability-wormholes and generating foamy oil flow. Experimental results indicate that CHOPS is superior to thermal methods in its lower operating costs and energy requirements. Heavy oil is considered to be environmentally problematic since non-hazardous oilfield wastes (NOW) are produced during exploration, drilling and refining. Several approaches have been addressed to lower the environmental impact for the CHOPS application in fields. One successful method is the slurry fracture injection (SFI). With incorporating solid wastes and water under fracture pressure into deep geological formations, SFI has shown considerable success in mitigating environmental issues for CHOPS development as well as its application in oilfields. Another promising method is the SuperSump method, which aims to achieve the sand free production.

This paper begins with a general discussion of CHOPS and the current waste treatment methods applied. Field experiences have seen the mitigation of environmental problems for SFI methods in Canada, Indonesia, etc. Then a detailed discussion on the mechanism of slurry fracture injection and the cases that the SFI method is successfully being used in oilfields, particularly on the environmentally friendly aspect. Specific attention is also extended to the upcoming Sand-Free method, along with its technology gaps in application. This paper ends with the future work on providing better environmental protection for CHOPS applications.