China Petroleum Chemical Corporation

Beijing Sinocep Engine Technology Co., Ltd.

China Petroleum & Chemical Corporation Exploration & Production Research Institute

Yusheng Ma

Li Wang

Zhengzhong Li

Changming Su

Lijun Guo

Qingxu Wang

Mengyun Zhao

Jianzheng Su

Rusheng Zhang

Qiulian Long

Suobing Zhang

Danian Zhang

Chenggang Zheng

Ming Li

A cationic copolymer represented by the following formula (I) has a viscosity average molecular weight in a range from 2 million to 10 million. In the cationic copolymer, the mole fractions of three structural units corresponding to three monomers are as follows: x being in a range from 0.01 to 20%, y being in a range from 0 to 15%, and z=1&#x2212;x&#x2212;y. When used in the construction of leaking stoppage in an oil well, a cationic chemical lost circulation additive prepared with the cationic copolymer is mixed with an anionic drilling fluid in a section of the wellbore where lost circulation occurs. Then neutral reaction and cross linking reaction occur, so that the viscosity of the resulting mixture rapidly increases to form a space grid structure. This blocks off the leakage path, and thus effects on efficient leaking stoppage in a short time period. 

Cationic copolymer and use thereof in lost circulation additive

A crank circular slider mechanism that includes a multi-row reciprocating motion part and a one-row reciprocating part. The multi-row reciprocating motion part has a guiding part divided by a longitudinal groove into two rows parallel to each other, each of which has a hole for a circular slider. The one-row reciprocating motion part has a guiding part which can be inserted into the longitudinal groove of the multi-row reciprocating motion part along the thickness direction, so as to vertically traverse the multi-row reciprocating motion part. The guiding part of the one-row reciprocating motion part includes a hole receiving a middle circular slider. Two circular sliders are mounted in the same phase; the middle circular slider is sandwiched therebetween and is located with a 180 degree phase difference compared to them. Adjacent circular sliders are secured to each other.

Crank circular sliding block mechanism and reciprocating member, cylinder block, internal combustion engine, and compressor

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Beijing, China

Yusheng Ma