In Decmber,15,2011, the Oil Production Plant ¢ñ of Zhongyuan Oilfield organized experts to make the technology achievement evaluation on the project “Research and Application of the Oil Recovery Enhancement Technology with Microsphere Profile Control in Zhongyuan” overtaken by our company. The ideas were as follows:
¢ñ. Main researches
1. The adaptability research of the oilfield microsphere profile control agent in Wenzhong1.
2. The formula research of the gel microsphere of Wenzhong Oilfield.
3. The overall scheme design and perfection of the deep profile control of the east experimental area in Wen25.
¢ò. Main innovation points
1. Research the influencial factors in the process of microsphere preparation. By adjusting such factors as the water-phase proportion, the hydrolysis degree and the cross-linking ratio, the microshpere with different granular size, degree of expansion and strength is attainable. As for the reservoir conditions of Wenzhong, several kinds of microsphere which are temperature-resist£¨<100¡æ£© and salinity-resist£¨<20×104mg/l£©have been successfully developed and on-line injection is realized.
2. Under the condition of the reservoir, the polymer gels that belong to two kinds cross-linking systems have been researched and formulas with different frozen time have been gained.
3. Adopted “PI+FD deep profile control comprehensive decision-making technology”. The gel microshpere deep profile control followed full profile control. According to the PI value and FD value and the change of the microsphere content carried by the output liquid in the process of profile control, the dynamic decision will be made. Multi-phase adjustment of the injection parameters (four “degree”) of the microsphere and multi-round profile control operation make the microsphere enter the deep formation step by step, lessen the contradiction between the inner layer and interlayer of the reservoirs, and improve the sweep volume of the injected water and enhance the oil recovery.
¢ó. Application conclusions
The project launched scientific research breakthrough endeavor on microsphere deep profile control. The microsphere was applicable to 9 well groups in Wenzhong oilfield. Compared with the statement before the profile control, the average injection pressure, the filling degree of the formation and the oil increased by 7.5MPa, 0.38, 2736t respectively. In 2011, under the condition of low productivity because of lack of new oil wells and lack of new measurements, the productivity of the whole block Wen25 Dong kept stably. This project improved the matching technology methods of the producing degree of the water flooding, which is significant to the water injection development in the similar complicated fault block which has enter the late period of high water content, whose production degree is great and which has experienced several round profile control.
¢ô. Overall evaluation
According to the expert group, this project launched the research targetedly, solved the manufacturing difficulties, and offered complete materials and accurate data. The acceptance was passed.