Abstract: A surfactant of formula (I) wherein each of R1 and R2 are independently a hydrogen, an optionally substituted alkyl, an optionally substituted cycloalkyl, or an optionally substituted arylalkyl, R3 and R4 are independently an optionally substituted alkyl, an optionally substituted cycloalkyl, or an optionally substituted arylalkyl, x is an integer in a range of 2-8, y is an integer in a range of 1-15, z is an integer in a range of 4-10, n is an integer in a range of 2-5, and A is one of a carboxybetaine group, a sulfobetaine group, or a hydroxy sulfobetaine group. An oil and gas well servicing fluid containing the surfactant and methods of servicing an oil and gas well are also described.

Abstract: A surfactant of formula (I) wherein each of R1 and R2 are independently a hydrogen, an optionally substituted alkyl, an optionally substituted cycloalkyl, or an optionally substituted arylalkyl, R3 and R4 are independently an optionally substituted alkyl, an optionally substituted cycloalkyl, or an optionally substituted arylalkyl, x is an integer in a range of 2-8, y is an integer in a range of 1-15, z is an integer in a range of 4-10, n is an integer in a range of 2-5, and A is one of a carboxybetaine group, a sulfobetaine group, or a hydroxy sulfobetaine group. An oil and gas well servicing fluid containing the surfactant and methods of servicing an oil and gas well are also described.

Abstract: 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.

Abstract: A surfactant of formula (I) wherein each of R1 and R2 are independently a hydrogen, an optionally substituted alkyl, an optionally substituted cycloalkyl, or an optionally substituted arylalkyl, R3 and R4 are independently an optionally substituted alkyl, an optionally substituted cycloalkyl, or an optionally substituted arylalkyl, x is an integer in a range of 2-8, y is an integer in a range of 1-15, z is an integer in a range of 4-10, n is an integer in a range of 2-5, and A is one of a carboxybetaine group, a sulfobetaine group, or a hydroxy sulfobetaine group. An oil and gas well servicing fluid containing the surfactant and methods of servicing an oil and gas well are also described.

Abstract: Methods of controlling clay swelling and stabilizing subterranean geological formations containing swellable clays (e.g., montmorillonite, bentonite) are described. The methods involve treating the swellable clays with a composition containing an amidoamine-based gemini surfactant. The gemini surfactant has dual chains connected via an alkylene linker, whereby each chain contains a quaternary ammonium head group and an ethoxylated alkyl tail. As examined by linear swelling and free swelling tests, use of the gemini surfactant is effective in reducing swelling of the clays.

Abstract: A drilling fluid formulation which includes an aqueous phase, and additives including an organophilic clay, a gemini surfactant, and a polyacrylamide. The organophilic clay contains an ion-exchange reaction product of a clay material (e.g. smectite) and quaternary ammonium cations. The polyacrylamide contains reacted units of an acrylamide monomer, an acrylate monomer, and a hydrophobicity modifying monomer. Rheology properties of the drilling fluid including gel strength, yield stress, and storage modulus are specified. The additives present in the drilling fluid synergistically boost its shale swelling inhibition capability.

Abstract: Amidoamine-based gemini surfactants having dual chains connected via an arylene or heteroarylene 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.

Abstract: Methods of controlling clay swelling and stabilizing subterranean geological formations containing swellable clays (e.g., montmorillonite, bentonite) are described. The methods involve treating the swellable clays with a composition containing an amidoamine-based gemini surfactant. The gemini surfactant has dual chains connected via an alkylene linker, whereby each chain contains a quaternary ammonium head group and an ethoxylated alkyl tail. As examined by linear swelling and free swelling tests, use of the gemini surfactant is effective in reducing swelling of the clays.

Abstract: Amidoamine-based gemini surfactants having dual chains connected via an arylene or heteroarylene 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.

Abstract: 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.

Abstract: A surfactant of formula (I) wherein each of R1 and R2 are independently a hydrogen, an optionally substituted alkyl, an optionally substituted cycloalkyl, or an optionally substituted arylalkyl, R3 and R4 are independently an optionally substituted alkyl, an optionally substituted cycloalkyl, or an optionally substituted arylalkyl, x is an integer in a range of 2-8, y is an integer in a range of 1-15, z is an integer in a range of 4-10, n is an integer in a range of 2-5, and A is one of a carboxybetaine group, a sulfobetaine group, or a hydroxy sulfobetaine group. An oil and gas well servicing fluid containing the surfactant and methods of servicing an oil and gas well are also described.

Abstract: A drilling fluid formulation which includes an aqueous phase, and additives including an organophilic clay, a gemini surfactant, and a polyacrylamide. The organophilic clay contains an ion-exchange reaction product of a clay material (e.g. smectite) and quaternary ammonium cations. The polyacrylamide contains reacted units of an acrylamide monomer, an acrylate monomer, and a hydrophobicity modifying monomer. Rheology properties of the drilling fluid including gel strength, yield stress, and storage modulus are specified. The additives present in the drilling fluid synergistically boost its shale swelling inhibition capability.