Abstract
Ignition design of air injection wells is the crucial factor to a successful in-situ combustion. In this paper, experimental studies were carried out on post steam flooding wells at JIN-91 of Liaohe oilfield for improving ignition success rate. The experiments were conducted by a high temperature-pressure ignition device specifically designed for in-situ combustion, and the effects of various parameters were investigated by factorial experiments. The results showed that the ignition temperature was reduced and the ignition time was shortened due to three factors: heating temperature, reservoir pressure, and clay minerals. When heating temperature exceeded 360 degrees C, experimental pressure was higher than 4.0 MPa, and 10% of montmorillonite clay was added, the crude oil samples could be ignited rapidly. According to the factorial results, the most effective method to shorten ignition time is by increasing heating temperature, the safest method to reduce crude oil spontaneous combustion temperature and to shorten ignition time is by applying clay minerals, and reservoir pressure is the key factor for safety operation during ignition operation. These results will provide experimental theoretical guidance for high efficiency ignition, process optimization, and safe implementation of crude oil reservoir, they also will deliver tech support for the high efficiency operation of in-situ combustion.
NSTL
Elsevier