Study And Application On Steam Stimulation Technology For Heavy Oil Reservoir In K Oilfield Of S Block In Kazakhstan

The area of heavy oil reservoir in K oilfield of S block in Kazakhstan belongs to semi-desert hilly plain, in which the saline land is widely developed. In the development process of conventional cold production, there were four main problems. The shallow buried depth of the reservoir and small production pressure difference affected the oil well production and stimulation effect. Poor fluidity of heavy oil led to the low production capacity. Gentle structure and serious edge-bottom water coning caused the rapid decline of the production. The unconsolidated formation, severe reservoir sand production and even the organic mixed fouling of sand and mud formed at the low temperature resulted in the sharp decline of the oil well production capacity. In order to improve the development effect of the heavy oil reservoir and in view of the problems existing in the development process, the research status of the steam stimulation at home and abroad were investigated and the geologic characteristics of the heavy oil reservoir in K oilfield of S block were comprehensively studied. The exploitation mode of natural exploitation, water flooding and steam stimulation were selected to analyze and demonstrate the feasibility of steam stimulation in the heavy oil reservoir in K oilfield of S block. By means of numerical simulation for the oil reservoir, the well type, well pattern and well spacing were optimized. At the same time, the parameters of steam injection velocity, steam quality, steam injection volume and soak time which influenced the effect of steam stimulation were optimized too. According to the deficiencies of the traditional sand control method, both the sand control well completion process and oil production technology were optimized and studied. Then, the final optimized design scheme was proposed and applied in the heavy oil reservoir in K oilfield of S block and good development effect was achieved. Steam stimulation technology was applied in 22 pilot oil wells. The highest daily oil production was 12.4t and the average oil production was 3 times as that before steam stimulation. The cumulative incremental oil production was 17292 t and its stimulation effect is obvious. The field application effect suggests that the steam stimulation technology is suitable for the heavy oil reservoir in K oilfield of S block in Kazakhstan, the development effect of the reservoir has been improved and the recovery percent of reserves is increased. All of theses have important guiding and reference significance on the development of other similar heavy oil reservoirs.