Calfee Halter & Griswold LLP
Additive composition suitable for viscosity reduction of oil-based drilling fluid, oil-based drilling fluid and use thereof
The present invention relates to the well drilling field in petroleum industry, in particular to an additive composition suitable for viscosity reduction of oil-based drilling fluids, an oil-based drilling fluid and use thereof. The double-block copolymer mainly consists of a block A and a block B, wherein, the block A is composed of structural units represented by formula (1), the block B is composed of structural units represented by formula (2), and the number-average molecular weight of the block A is 1,500-10,000. The double-block copolymer provided in the present invention can be used as a viscosity reducer in oil-based drilling fluids, especially can be used as a viscosity reducer in high-density clay-free oil-based drilling fluids, and can greatly decrease the apparent viscosity and plastic viscosity of oil-based drilling fluids in high-temperature and high-pressure reservoir while maintaining appropriate shearing force, so as to increase the drilling rate and reduce drilling difficulties.
China University of Petroleum (Beijing)
C C C C
C09K C08F C09K C09K
inventional inventional inventional additional
Kai Lili Xinliang Yawei Li Chunlei Fan Shuanglei Guancheng Yinbo Gang Deli Zhengqiang Guangchang
Wang Yang Li Shi Zhao Wang Liu Peng Jiang He Qu Gao Deng Ma