China University of Petroleum

Cnpc Engineering Technology R&d Company Limited

Yuping Yang

Jingping Liu

Long Li

Wei Zhang

Yan Zhang

Ying Wang

Lei Guo

Jinsheng Sun

Min Chang

Lulu Li

Dongyang Li

Jinhong Wang

Yushuang Liu

Pingliang Fang

Weiwei Hao

A filtrate reducer for temperature-resistant calcium-resistant water-based drilling fluid used in oil and gas reservoir protection, a drilling fluid, and uses of the filtrate reducer and the drilling fluid are described. The filtrate reducer contains structural units represented by formulas (1), (2), and (3) herein. The water-based drilling fluid contains the filtrate reducer, and exhibits good inhibitive, rheological, filtrate reducing, and reservoir protection performance when it is applied in the drilling process in a high-temperature high-calcium deep salt-gypsum formation.

Filtrate reducer for temperature-resistant calcium-resistant water-based drilling fluid used in oil and gas reservoir protection, drilling fluid, and uses thereof

A temperature-resistant calcium-resistant water-based drilling fluid for oil and gas reservoir protection and a use thereof is provided. The water-based drilling fluid contains a filtrate reducer and a plugging agent, wherein the filtrate reducer is a copolymer that contains structural units represented by formula (1), structural units represented by formula (2), and structural units represented by formula (3), wherein, the mass ratio of the structural units represented by formula (1) to the structural units represented by formula (2) to the structural units represented by formula (3) is (0.1-0.2):1:(0.05-0.1), and the number-average molecular weight of the copolymer is 10,000-100,000, the plugging agent is acrylamide-diallyldimethylammonium chloride copolymer modified graphene. The water-based drilling fluid described can exhibit excellent filtrate reducing, plugging, temperature-resistant, anti-collapsing, and reservoir protective performance when it is applied in well drilling in deep high-temperature wells.

Temperature-resistant calcium-resistant water-based drilling fluid for oil and gas reservoir protection and use thereof

The present invention relates to the technical field of well drilling, and discloses a plugging agent for temperature-resistant calcium-resistant water-based drilling fluid used in oil and gas reservoir protection, a drilling fluid, and uses of the plugging agent and the drilling fluid. The plugging agent for temperature-resistant calcium-resistant water-based drilling fluid used in oil and gas reservoir protection contains acrylamide-diallyldimethylammonium chloride copolymer modified graphene, wherein in the acrylamide-diallyldimethylammonium chloride copolymer, a molar ratio of structural units provided by acrylamide to structural units provided by diallyldimethylammonium chloride is 1:5-15, and the number-average molecular weight of the acrylamide-diallyldimethylammonium chloride copolymer is 15,000-30,000. The water-based drilling fluid described in the present invention is especially applicable to well drilling in deep salt-gypsum formations, and can exhibit good filtrate reducing, plugging, temperature-resistant, anti-collapsing, and reservoir protection performance.

Plugging agent for temperature-resistant calcium-resistant water-based drilling fluid used in oil and gas reservoir protection, drilling fluid, and uses thereof

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Beijing, China

Yuping Yang