The present disclosure provides a drilling fluid lubricant and a preparation method and use thereof. The preparation method includes steps of: 1) mixing styrene and water, then adding a nano-inorganic intermediate, a crosslinking agent and an emulsifier and stirring to obtain a first mixture; 2) under an inert atmosphere, stirring the first mixture to obtain an intermediate emulsion; then heating the intermediate emulsion to 70-85° C., then adding an initiator, keeping temperature and stirring for 7-10 hours to obtain an emulsion of polystyrene nanocomposite with a particle size of 40-90 nm; the emulsion of polystyrene nanocomposite being sequentially subjected to a granulating treatment to obtain polystyrene nanocomposite particles; 3) mixing industrial base oil, polystyrene nanocomposite particles and industrial oleic acid, and stirring evenly at room temperature to obtain the drilling fluid lubricant.

A method of treating a well comprising introducing a well treatment fluid into the well, and a well treatment fluid, are provided. The well treatment fluid comprises an aqueous base fluid, sepiolite clay, and a polymer component selected from the group of an acryloylmorpholine polymer, a polyvinylpyrrolidone polymer, and mixtures thereof. In one embodiment, for example, the method is a method of drilling a well. In this embodiment, the well treatment fluid is a drilling fluid.

A method of treating a well comprising introducing a well treatment fluid into the well, and a well treatment fluid, are provided. The well treatment fluid comprises an aqueous base fluid, sepiolite clay, and a polymer component selected from the group of an acryloylmorpholine polymer, a polyvinylpyrrolidone polymer, and mixtures thereof. In one embodiment, for example, the method is a method of drilling a well. In this embodiment, the well treatment fluid is a drilling fluid.

The present invention relates to substituted saccharides or glycosides and their use in drilling fluid compositions. The substituted saccharide or glycoside bears a substituent A, a substituent B and a substituent C, wherein the substituent A comprises in its structure a group ##STR00001##
the substituent B comprises in its structure a group ##STR00002##
and the substituent C comprises in its structure a unit —NH—R.sub.7—. The definition of each group is described in the description. The drilling fluid composition can show good temperature resistance, filtration loss reducing reduction property, pollution resistance, inhibition property, lubricating property or reservoir protection property, and has no biotoxicity.

The present invention relates to substituted saccharides or glycosides and their use in drilling fluid compositions. The substituted saccharide or glycoside bears a substituent A, a substituent B and a substituent C, wherein the substituent A comprises in its structure a group ##STR00001##
the substituent B comprises in its structure a group ##STR00002##
and the substituent C comprises in its structure a unit —NH—R.sub.7—. The definition of each group is described in the description. The drilling fluid composition can show good temperature resistance, filtration loss reducing reduction property, pollution resistance, inhibition property, lubricating property or reservoir protection property, and has no biotoxicity.

Aspects of the present invention provide methods of drying lecithin in a batch reaction, comprising the steps of obtaining a lecithin-containing material (derived from a crude refining stream) comprising 15-50% water, 10-30% acetone insoluble matter, and 10-20% free fatty acid; adding a fatty acid source (also derived from a crude refining stream) to the lecithin-containing material composition to obtain a lecithin/fatty acid reaction mixture; and blowing dry gas through the gum/fatty acid reaction mixture to obtain a resultant dried lecithin fatty acid blend having a water content of less than 2%. The resultant dried lecithin fatty acid blend may be used in asphalt or oil field applications.

Aspects of the present invention provide methods of drying lecithin in a batch reaction, comprising the steps of obtaining a lecithin-containing material (derived from a crude refining stream) comprising 15-50% water, 10-30% acetone insoluble matter, and 10-20% free fatty acid; adding a fatty acid source (also derived from a crude refining stream) to the lecithin-containing material composition to obtain a lecithin/fatty acid reaction mixture; and blowing dry gas through the gum/fatty acid reaction mixture to obtain a resultant dried lecithin fatty acid blend having a water content of less than 2%. The resultant dried lecithin fatty acid blend may be used in asphalt or oil field applications.

Amidoamine-based gemini surfactants having dual chains connected via an alkenylene or alkynylene linker. Each chain contains a quaternary ammonium head group and an ethoxylated alkyl tail. A water-based drilling fluid containing the gemini surfactant is also provided. As examined by linear swelling and free swelling tests, the gemini surfactant is effective in reducing clay swelling.

A method of removing calcium-containing water-based filter cake from a wellbore involving contacting the calcium-containing filter cake with a biodegradable acid solution of water, hydrochloric acid, formic acid, citric acid, and a surfactant. The method is performed at a pressure of 200 to 400 psi and a temperature of 50 to 125° C. The method removes calcium-containing filter cake made of water, calcium carbonate, a polymer or starch and a clay. The method meets industry standard steel corrosion rates of less than 0.049 lb/ft.sup.2 per day. Also disclosed is a biodegradable acid solution of water, hydrochloric acid, formic acid, citric acid, and a surfactant that meets OECD 301B thresholds for ready biodegradability.

A method of removing calcium-containing water-based filter cake from a wellbore involving contacting the calcium-containing filter cake with a biodegradable acid solution of water, hydrochloric acid, formic acid, citric acid, and a surfactant. The method is performed at a pressure of 200 to 400 psi and a temperature of 50 to 125° C. The method removes calcium-containing filter cake made of water, calcium carbonate, a polymer or starch and a clay. The method meets industry standard steel corrosion rates of less than 0.049 lb/ft.sup.2 per day. Also disclosed is a biodegradable acid solution of water, hydrochloric acid, formic acid, citric acid, and a surfactant that meets OECD 301B thresholds for ready biodegradability.