Abstract: Methods and related systems are configured to treat a drilling fluid to cause water droplets to coalesce. One or more phases are thereafter separated from the treated drilling fluid. The oil and/or solids separated from the treated drilling fluid may be added to a base fluid.

Abstract: Compositions including relatively low reactivity acids and having a pH of from about 2 to about 5, mixed with viscoelastic surfactants (VESs) and internal breakers may serve as fluids, in a non-limiting embodiment as drill-in fluids, to open underground hydrocarbon reservoirs with carbonate contents of 10 wt % or above. The fluids initially have low viscosities. After the fluid flows out of the drill bit, the acids react with carbonates in the formation thereby increasing the pH of the fluids causing the VES to gel the fluid at the bottom of the hole and within the formation rock. Even when the subterranean formation contains naturally-occurring fractures, the viscosified fluid will reduce fluid loss into the formation. After drilling through the targeted formation, internal breakers in the viscosified fluids will break down the fluids to permit their removal, and production of the well with very little or no near well bore damage.

Abstract: Compounds of formula (I): wherein: R2 is H or an optionally substituted C1-4 alkyl group; Y is either —(CH2)n—X—, where n is 1 or 2 and X is O, S, S(?O), S(?O)2, or NRN1, where RN1 is selected from H or optionally substituted C1-4 alkyl, or Y is —C(?O)NRN2—, where RN2 is selected from H, and optionally substituted C1-7 alkyl or C5-20 aryl; R3 is an optionally substituted C6 aryl group linked to a further optionally substituted C6 aryl group, wherein if both C6 aryl groups are benzene rings, there may be an oxygen bridge between the two rings, bound adjacent the link on both rings; A is a single bond or a C1-3 alkylene group; and R5 is either: (i) carboxy; (ii) a group of formula (II): or (iii) a group of formula (III): wherein R is optionally substituted C1-7 alkyl, C5-20 aryl or NRN3RN4, where RN3 and RN4 are independently selected from optionally substituted alkyl; (iv) tetrazol-5-yl.

Abstract: Fluids containing liquid crystal-forming surfactants or polymeric surfactants, or polymers, or complex polymers or copolymers, or graphite nanotubes or Janus particles in a polar and/or non polar liquid, and optionally, co-surfactants, are useful in drilling, completion and production operations to give increased viscosity (solids suspension ability) and/or decreased fluid loss, as compared to otherwise identical fluids absent the liquid crystals. These liquid crystal compositions contain organized micelles. The liquid crystal-containing fluids are useful in completion fluids, fracturing fluids, formation damage remediation, waste management, lost circulation, drilling optimization, reducing trapped annular pressure during the hydrocarbon production process, well strengthening, friction and drag reducers, fluids introduced through an injection well, for geothermal wells, and the controlled release of additives into a wellbore, at a subterranean formation or at the oil production facilities.

Abstract: Single phase microemulsions improve the removal of filter cakes formed during drilling with oil-based muds (OBMs). The single phase microemulsion removes oil and solids from the deposited filter cake. Optionally, an acid capable of solubilizing the filter cake bridging particles may also be used with the microemulsion. In one non-limiting embodiment the acid may be a polyamino carboxylic acid. Skin damage removal from internal and external filter cake deposition can be reduced. In another optional embodiment, the single phase microemulsion may contain a filtration control additive for delaying the filter cake removal, destruction or conversion.

Abstract: Nanoemulsions, miniemulsions, microemulsion systems with excess oil or water or both (Winsor III) or single phase microemulsions (Winsor IV) may be pre-formed and used as one or more fluid pills during hydrocarbon recovery operations after drilling with OBM or SBM. The nanoemulsions, miniemulsions, microemulsion systems with excess oil or water or both or single phase microemulsions remove oil and solids from the well and wellbore surfaces. In one non-limiting embodiment, a single phase microemulsion (SPME) or other pre-formed fluid may be created from a polar phase, a nonpolar phase, an optional viscosifier, and at least one surfactant.

Abstract: Single phase microemulsions improve the removal of filter cakes formed during drilling with oil-based muds (OBMs). The single phase microemulsion removes oil and solids from the deposited filter cake. Optionally, an acid capable of solubilizing the filter cake bridging particles may also be used with the microemulsion. In one non-limiting embodiment the acid may be a polyamino carboxylic acid. Skin damage removal from internal and external filter cake deposition can be reduced. In another optional embodiment, the single phase microemulsion may contain a filtration control additive for delaying the filter cake removal, destruction or conversion.

Abstract: Nanoemulsions have been discovered to be useful to the oil field. More particularly water-in-oil (W/O), oil-in-water (O/W) and other classes of nanoemulsions have found beneficial application in drilling, completion, well remediation and other oil and gas industry related operations. Additionally, nanoemulsions may reduce friction pressure losses, as well as reduce subsidence of solid weight material during oil and gas operations. New preparation methods for nanoemulsions have also been discovered.

Abstract: Single phase microemulsions improve the removal of filter cakes formed during drilling with oil-based muds (OBMs). The single phase microemulsion removes oil and solids from the deposited filter cake. Optionally, an acid capable of solubilizing the filter cake bridging particles may also be used with the microemulsion. In one non-limiting embodiment the acid may be a polyamino carboxylic acid. Skin damage removal from internal and external filter cake deposition can be reduced. In another optional embodiment, the single phase microemulsion may contain a filtration control additive for delaying the filter cake removal, destruction or conversion.

Abstract: Single phase microemulsions improve the removal of filter cakes formed during drilling with invert emulsions. The single phase microemulsion removes oil and solids from the deposited filter cake. Optionally, an acid capable of solubilizing the filter cake bridging particles may also be used with the microemulsion. In one non-limiting embodiment the acid may be a polyamino carboxylic acid. Skin damage removal from internal and external filter cake deposition can be reduced.

Abstract: Single-phase microemulsions (SPMES) and in situ-formed microemulsions in water-wetting pills may be used to reverse the wettability of subterranean rock previously drilled with an oil-based mud or synthetic-based mud before pumping a high fluid loss squeeze pill or crosslink pill or other water-based pill. This wettability reversal occurs by solubilization of the non-polar material into the microemulsion when the water-wetting pill contacts the non-polar material. An in situ microemulsion may be formed when one or more surfactant and a polar phase (e.g. water or brine), and eventually some amount of organic phase, contacts the reservoir formation and reverses the wettability encountered in the porous media. The microemulsions are effective for reversing the wettability that occurs from non-polar materials which include, but are not necessarily limited to, oil-based mud, synthetic-based mud, paraffins, asphaltenes, emulsions, slugs, and combinations thereof.

Abstract: Mesophase fluids may be pre-formed or formed in situ and may be used downhole for various treatments including, but not limited to, cleaning up and removing non-polar materials from reservoir production zones, removing wellbore damage, releasing stuck pipe, components in spacers and pills and the like in oil and gas wells. These treatments involve solubilization of the non-polar material into the emulsion when the treatment fluid contacts non-polar materials. These mesophase fluids use extended chain surfactants having propoxylated/ethoxylated spacer arms. The extended chain surfactants are intramolecular mixtures containing hydrophilic and lipophilic portions. They attain high solubilization in the mesophase fluids (e.g. single phase microemulsions), are in some instances insensitive to temperature and are useful for a wide variety of oil types.

Abstract: Compounds of formula (X): wherein: R2 is H or an optionally substituted C1-4 alkyl group; Y is either —(CH2)n—X—, where n is 1 or 2 and X is O, S, S(?O), S(?O)2, or NRN1, where RN1 is selected from H or optionally substituted C1-4 alkyl, or Y is —C(?O)NRN2—, where RN2 is selected from H, and optionally substituted C1-7 alkyl or C5-20 aryl; R3 is an optionally substituted C6 aryl group linked to a further optionally substituted C6 aryl group, wherein if both C6 aryl groups are benzene rings, there may be an oxygen bridge between the two rings, bound adjacent the link on both rings; A is a single bond or a C1-3 alkylene group; and R5 is either: (i) carboxy; (ii) a group of formula (II): or (iii) a group of formula (III): wherein R is optionally substituted C1-7 alkyl, C5-20 aryl or NRN3RN4, where RN3 and RN4 are independently selected from optionally substituted alkyl; (iv) tetrazol-5-yl.

Abstract: Compounds of formula (I): wherein: R2 is H or an optionally substituted C1-4 alkyl group; Y is either —(CH2)n—X—, where n is 1 or 2 and X is O, S, S(?O), S(?O)2, or NRN1, where RN1 is selected from H or optionally substituted C1-4 alkyl, or Y is —C(?O)NRN2—, where RN2 is selected from H, and optionally substituted C1-7 alkyl or C5-20 aryl; R3 is an optionally substituted C6 aryl group linked to a further optionally substituted C6 aryl group, wherein if both C6 aryl groups are benzene rings, there may be an oxygen bridge between the two rings, bound adjacent the link on both rings; A is a single bond or a C1-3 alkylene group; and R5 is either: (i) carboxy; (ii) a group of formula (II): (iii) a group of formula (III): wherein R is optionally substituted C1-7 alkyl, C5-20 aryl or NRN3RN4, where RN3 and RN4 are independently selected from optionally substituted C1-4 alkyl; (iv) tetrazol-5-yl.

Abstract: Compounds of formula (I): wherein: R2 is H or an optionally substituted C1-4 alkyl group; Y is either —(CH2)n—X—, where n is 1 or 2 and X is O, S, S(?O), S(?O)2, or NRN1, where RN1 is selected from H or optionally substituted C1-4 alkyl, or Y is —C(?O)NRN2—, where RN2 is selected from H, and optionally substituted C1-7 alkyl or C5-20 aryl; R3 is an optionally substituted C6 aryl group linked to a further optionally substituted C6 aryl group, wherein if both C6 aryl groups are benzene rings, there may be an oxygen bridge between the two rings, bound adjacent the link on both rings; A is a single bond or a C1-3 alkylene group; and R5 is either: (i) carboxy; (ii) a group of formula (II): (iii) a group of formula (III): wherein R is optionally substituted C1-7 alkyl, C5-20 aryl or NRN3RN4, where RN3 and RN4 are independently selected from optionally substituted C1-4 alkyl; (iv) tetrazol-5-yl.

Abstract: Single phase microemulsions (SPMEs) and in situ-formed microemulsions may be used to clean up and remove non-polar materials from reservoir production zones of oil and gas wells. This clean up occurs by solubilization of the non-polar material into the microemulsion when the treatment fluid contacts the non-polar material. An in situ microemulsion may be formed when one or more surfactant and a polar phase (e.g. water or brine), and eventually some small amount of organic phase, contacts the reservoir formation and solubilizes the non-polar material encountered in the porous media. The microemulsions are effective for removing the formation damage caused by non-polar materials which include, but are not necessarily limited to oil-based mud, synthetic-based mud, paraffins, asphaltenes, emulsions, slugs, and combinations thereof.

Abstract: Nanoemulsion, macroemulsions, miniemulsions, microemulsion systems with excess oil or water or both (Winsor I, II or III phase behavior) or single phase microemulsions (Winsor IV) improve the removal of filter cakes formed during hydrocarbon reservoir wellbore drilling with OBM. Such filter cakes and their particles can contact, impact and affect the movement of the drill string undesirably resulting in a “stuck pipe” condition. The macroemulsion, nanoemulsion, miniemulsion, microemulsion systems with excess oil or water or both or single phase microemulsion removes oil and solids from the filter cake, thereby releasing the drill string from its stuck condition. In one non-limiting embodiment, the emulsion system may be formed in situ (downhole) rather than produced or prepared in advance and pumped downhole.

Abstract: Nanoemulsions, miniemulsions, microemulsion systems with excess oil or water or both (Winsor III) or single phase microemulsions (Winsor IV) may be formed in situ during hydrocarbon recovery operations after drilling with OBM or SBM using one or more fluid pills. The nanoemulsions, miniemulsions, microemulsion systems with excess oil or water or both or single phase microemulsions remove oil and solids from the well and wellbore surfaces. In one non-limiting embodiment, a single phase microemulsion (SPME) or other in situ-formed fluid may be created from a polar phase, a nonpolar phase, at least one viscosifier, and at least one surfactant.

Abstract: Nanoemulsion, macroemulsions, miniemulsions, microemulsion systems with excess oil or water or both (Winsor I, II or III phase behavior) or single phase microemulsions (Winsor IV) improve the removal of filter cakes formed during hydrocarbon reservoir wellbore drilling with OBM. The macroemulsion, nanoemulsion, miniemulsion, microemulsion systems with excess oil or water or both or single phase microemulsion removes oil and solids from the deposited filter cake. In one non-limiting embodiment, the emulsion system (e.g. single phase microemulsion, nanoemulsion, or other emulsions) may be formed in situ (downhole) rather than produced or prepared in advance and pumped downhole. Skin damage removal from internal and external filter cake deposition can be reduced.

Abstract: Compounds of formula (I): wherein: R2 is H or an optionally substituted C1-4 alkyl group; Y is either —(CH2)n—X—, where n is 1 or 2 and X is O, S, S(?O), S(?O)2, or NRN1, where RN1 is selected from H or optionally substituted C1-4 alkyl, or Y is —C(?O)NRN2—, where RN2 is selected from H, and optionally substituted C1-7 alkyl or C5-20 aryl; R3 is an optionally substituted C6 aryl group linked to a further optionally substituted C6 aryl group, wherein if both C6 aryl groups are benzene rings, there may be an oxygen bridge between the two rings, bound adjacent the link on both rings; A is a single bond or a C1-3 alkylene group; and R5 is either: (i) carboxy; (ii) a group of formula (II): or (iii) a group of formula (III): ?wherein R is optionally substituted C1-7 alkyl, C5-20 aryl or NRN3RN4, where RN3 and RN4 are independently selected from optionally substituted C1-4 alkyl; (iv) tetrazol-5-yl.