Abstract: The present invention relates to the well drilling field in petrochemical industry, in particular to use of dual-cation fluorocarbon surfactant as amphiphobic wettability reversal agent in drilling fluid. The dual-cation fluorocarbon surfactant is a dual-cation fluorocarbon surfactant of which the cation part is represented by the following formula (1). The dual-cation fluorocarbon surfactant of the present invention can serve as wettability reversal agent when it is used for oil-gas drilling to enable rock amphiphobic, and is an amphiphobic wettability reversal agent which can cause rock surface to be non-hydrophilic and non-lipophilic. Using of dual-cation fluorocarbon surfactant, especially when drilling highly hydrous mud shale, can avoid permeation of water and oil into the rock effectively and thereby a capillary phenomenon can be prevented, and an effect of stabilizing the well wall and protecting the reservoir is attained.

Abstract: A super-amphiphobic composite material and use of the same as an inhibitor, lubricant, reservoir protectant, and accelerator in water-based drilling fluids. A method for preparing the amphiphobic composite material includes: performing a first mixing of nano-titanium dioxide and nano-silicon dioxide in an alcohol-water mixed solvent under an alkaline condition, to obtain a dispersion of nano-titanium dioxide and nano-silicon dioxide; then introducing a fluorosilicone-containing coupler into the dispersion of nano-titanium dioxide and nano-silicon dioxide and performing a second mixing. The amphiphobic composite material may be applied in water-based drilling fluids. It has an effect of strongly inhibiting hydrated swelling and disintegration, low toxicity and high compatibility; can solve problems such as well wall instability, blockage of drilling tools, and reservoir damage, etc.

Abstract: The present invention relates to the well drilling field in petrochemical industry, in particular to use of dual-cation fluorocarbon surfactant as amphiphobic wettability reversal agent in drilling fluid. The dual-cation fluorocarbon surfactant is a dual-cation fluorocarbon surfactant of which the cation part is represented by the following formula (1). The dual-cation fluorocarbon surfactant of the present invention can serve as wettability reversal agent when it is used for oil-gas drilling to enable rock amphiphobic, and is an amphiphobic wettability reversal agent which can cause rock surface to be non-hydrophilic and non-lipophilic. Using of dual-cation fluorocarbon surfactant, especially when drilling highly hydrous mud shale, can avoid permeation of water and oil into the rock effectively and thereby a capillary phenomenon can be prevented, and an effect of stabilizing the well wall and protecting the reservoir is attained.

Abstract: The present invention relates to the well drilling field in petroleum industry, in particular to a drilling fluid additive composition that contains a lubricant, an emulsifier, and a rheological modifier, wherein, the lubricant contains: graphite oxide and a biquaternary ammonium salt compound in which the cation part is represented by formula (1); the emulsifier is one or more of compounds represented by formula (I); the rheological modifier is a dimer acid-organic amine copolymer comprising structural units from dimer acid, structural units from alkylamine and structural units from arylamine. The present invention further provides an oil-based drilling fluid containing the composition and a use thereof.

Abstract: The present invention relates to the well drilling field in petroleum industry, in particular to a drilling fluid additive composition and a water-based drilling fluid suitable for high pressure plugging while drilling. The composition contains a bridging agent, a nano-plugging agent, a rheological modifier, a bionic wall bracing agent, and a bionic shale inhibitor, wherein, the bridging agent is a weak-crosslinked copolymer, in which the content of cross-linker structures is 0.1-1 wt. %; the nano-plugging agent is modified nanometer silicon dioxide particles; the rheological modifier is a dimer acid-organic amine copolymer; and the bionic wall bracing agent is carboxymethyl chitosan with a dopamine-derived base group grafted on its main chain.

Abstract: The present invention relates to the well drilling field in petroleum industry, in particular to a drilling fluid additive composition that contains a lubricant, an emulsifier, and a rheological modifier, wherein, the lubricant contains: graphite oxide and a biquaternary ammonium salt compound in which the cation part is represented by formula (1); the emulsifier is one or more of compounds represented by formula (I); the rheological modifier is a dimer acid-organic amine copolymer comprising structural units from dimer acid, structural units from alkylamine and structural units from arylamine. The present invention further provides an oil-based drilling fluid containing the composition and a use thereof. The oil-based drilling fluid containing the composition provided in the present invention obtains a lower lubrication coefficient, and favorable rheological property and thermostability, and is suitable for use in operation at a high temperature.

Abstract: The present invention relates to the well drilling field in petrochemical industry, and discloses a drilling fluid additive composition comprising a nano-plugging agent, a bionic wall bracing agent, a bionic shale inhibitor, an emulsifier, and an amphiphobic wettability reversal agent, wherein, the nano-plugging agent is modified silicon dioxide nano-particle, and its modifying group includes a modifying copolymer chain; the bionic wall bracing agent is carboxymethyl chitosan with a dopamine-derived group grafted on its main chain; the bionic shale inhibitor is composed of structural units of arginine and structural units of lysine; and the amphiphobic wettability reversal agent is a dual-cation fluorocarbon surfactant. The present invention further provides a pseudo oil-based drilling fluid suitable for horizontal shale gas wells containing the above composition.

Abstract: The present invention relates to the well drilling field in petrochemical industry, and discloses a drilling fluid additive composition comprising a nano-plugging agent, a bionic wall bracing agent, a bionic shale inhibitor, an emulsifier, and an amphiphobic wettability reversal agent, wherein, the nano-plugging agent is modified silicon dioxide nano-particle, and its modifying group includes a modifying copolymer chain; the bionic wall bracing agent is carboxymethyl chitosan with a dopamine-derived group grafted on its main chain; the bionic shale inhibitor is composed of structural units of arginine and structural units of lysine; and the amphiphobic wettability reversal agent is a dual-cation fluorocarbon surfactant. The present invention further provides a pseudo oil-based drilling fluid suitable for horizontal shale gas wells containing the above composition.

Abstract: The present invention relates to the well drilling field in petrochemical industry, and discloses a high-density water-based drilling fluid suitable for horizontal shale gas wells comprising a nano-plugging agent, a bionic wall bracing agent, a bionic shale inhibitor, a filler, an emulsifier, and an amphiphobic wettability reversal agent, wherein, the nano-plugging agent is modified silicon dioxide nano-particle, and its modifying group includes a modifying copolymer chain; the bionic wall bracing agent is carboxymethyl chitosan with a dopamine-derived group grafted on its main chain; the bionic shale inhibitor is composed of structural units of arginine and structural units of lysine; the filler consists of calcium carbonate of 1,600-2,500 mesh, calcium carbonate of 1,050-1,500 mesh, and calcium carbonate of 500-1,000 mesh at a weight ratio of 1:0.55-6:0.55-6; and the amphiphobic wettability reversal agent is a dual-cation fluorocarbon surfactant.

Abstract: The present invention relates to the petroleum drilling fluid field, and discloses a modified silicon dioxide nano-particle comprising a modifying polymer chain composed of structural units provided by one or more of monomers represented by the following formula (1) and one or more of monomers represented by the following formula (2). The present invention provides a method for preparing modified silicon dioxide nano-particles and a drilling fluid suitable for shale gas wells containing the modified silicon dioxide nano-particles as a plugging agent. When the modified silicon dioxide nano-particles provided in the present invention are used as a plugging agent in a drilling fluid, they will not agglomerate into large-size particles, and can achieve a good plugging effect.

Abstract: The present invention relates to the well drilling field in petrochemical industry, and discloses an environment-friendly water-based drilling fluid applicable to horizontal shale gas wells comprising a nano-plugging agent, a bionic wall bracing agent, a bionic shale inhibitor, a filler, an emulsifier, and an amphiphobic wettability reversal agent, wherein, the nano-plugging agent is modified silicon dioxide nano-particle, and its modifying group includes an acrylic copolymer chain; the bionic wall bracing agent is carboxymethyl chitosan with a dopamine-derived group grafted on its main chain; the bionic shale inhibitor is composed of structural units of arginine and structural units of lysine; the filler consists of calcium carbonate of 1,600-2,500 mesh, calcium carbonate of 1,050-1,500 mesh, and calcium carbonate of 500-1,000 mesh at a weight ratio of 1:0.55-6:0.55-6; and the amphiphobic wettability reversal agent is a dual-cation fluorocarbon surfactant.

Abstract: The present invention relates to the well drilling field in petrochemical industry, and discloses a drilling fluid additive composition and water-based drilling fluid suitable for horizontal shale gas wells. The composition comprises a nano-plugging agent, a bionic wall bracing agent, a bionic shale inhibitor, an emulsifier, and an amphiphobic wettability reversal agent, wherein, the nano-plugging agent is modified silicon dioxide nano-particles, and its modifying group includes an acrylic copolymer chain; the bionic wall bracing agent is carboxymethyl chitosan with a dopamine-derived group grafted on its main chain; the bionic shale inhibitor is composed of structural units of arginine and structural units of lysine; and the amphiphobic wettability reversal agent is a dual-cation fluorocarbon surfactant.

Abstract: 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.

Abstract: The present subject matter relates to the drilling fluid field, and discloses a viscosifier for oil-based drilling fluids and a method for preparing the viscosifier for oil-based drilling fluids. The preparation method comprises the following steps: (1) mixing an initiator with an unsaturated amide, an unsaturated organic sulfonic acid, and an unsaturated organic carboxylic acid in an aqueous phase solution and initiating a polymerization reaction with an oil phase solution that contains emulsifier and base oil, to obtain a polymer emulsion; (2) purifying and drying the polymer emulsion to obtain a composition; (3) mix the composition, sepiolite powder, and an acid while stirring, and then drying the obtained mixture. The viscosifier for oil-based drilling fluids disclosed in the present subject matter can make up for the shortage of viscosifiers for oil-based drilling fluids in the art, and has favorable temperature tolerance property, viscosity improvement property and environmental friendliness.