WanFu, Zhou (Daqing Oilfield Co. Ltd) | ZhongLian, Han (Daqing Oilfield Co. Ltd) | Gang, Cao (Daqing Oilfield Co. Ltd) | Xin, Wang (Daqing Oilfield Co. Ltd) | QingGuo, Wang (Daqing Oilfield Co. Ltd) | WenJiang, Chen (Daqing Oilfield Co. Ltd) | QingSong, Li (Daqing Oilfield Co. Ltd) | JingMei, Wang (Daqing Oilfield Co. Ltd) | Yang, Han (Daqing Oilfield Co. Ltd) | HaiRong, Fu (Daqing Oilfield Co. Ltd)
In the later stage of development, most oilfields faced high water cut issue after treatments. Meanwhile, how to effectively control oil wells water breakthrough after fracturing so as to increase oil production has become a big challenge for production engineers. This paper introduced a novel selective proppant which can effectively block water from entering well bore after fracturing.
Based on "eggshell principle" and interfacial tension theory, this novel proppant was developed with a new monolayer strong hydrophobic interface treatment technique. This special processing technique could not only reduce the proppant's flow resistance of oil, but also increase its flow resistance of water. As the result, this novel proppant showed the characteristics of excellent lipophilicity and hydrophobicity as well. Experiments indicated that oil water diversion ratio of selective proppant was greater than 1.2, while the ordinary proppant was less than 0.7. The oil wettability index of selective proppant was greater than 0.8, while the ordinary proppant was less than 0.3. The main characteristics of this supporting agent was small apparent density, low broken rate, and high flow capacity. The proppant surface is oil wet, which has the characteristics of oil increasing precipitation. Experiments showed that the seepage velocity of water in selective proppant was obviously lower than in quartz sand, selective proppant with water resistance.
Field test was carried out in 11 wells with selective proppant fracturing. A group of conventional fracturing wells were selected as contrasted wells with similar reservoir and operating conditions. After fracturing with novel proppant, the average water cut of producers was decreased by 7.2% per well, the average oil production was increased by 6.3 tons per well, and the average valid fracturing a period was 14.1 months. As for contrasted wells with conventional fracturing proppant, the average single well water cut decline was only 0.4%, the average single well daily oil 3.1 tons, an average period of only 5.8 months.
The novel proppant showed remarkable advantages in improving oil production and decreasing water cut. This technique has a great future for mature oilfield development.