Abstract: Systems and methods for producing a reversible hemiaminal or aminal gel composition for use in 3D printing, the method including preparing a liquid precursor composition, the liquid precursor composition operable to remain in a first liquid state at about room temperature, where the liquid precursor composition comprises: an organic amine composition; an aldehyde composition; a polar aprotic organic solvent; and a carbon nanomaterial; heating the liquid precursor composition to transition from the liquid state to a gel state; transitioning the gel state to a second liquid state; and 3D printing a solid carbon nanomaterial object comprising a solid printed gel from the second liquid state with a pre-determined orientation for the carbon nanomaterial.

Abstract: A precursor cement slurry includes a cement powder, water, and an additive. The additive includes a cement bond enhancer and a non-aqueous fluid additive. The non-aqueous fluid additive is an internal phase and the cement bond enhancer stabilizes the non-aqueous fluid additive in the form of a Pickering emulsion within the precursor cement slurry. The cement bond enhancer is comprised of the reaction product of graphene oxide with an anchoring functionality. A method of forming the precursor cement slurry and a method of cementing an annular space within a wellbore are also provided.

Abstract: A process for making a layered multi-material structural element having controlled mechanical failure characteristics. The process includes the steps of: supplying a cementitious layer and forming a polymer layer on the cementitious layer by additive manufacture such that the polymer layer has a first thickness and the cementitious layer has a second thickness, wherein the polymer layer comprises a polymer and the cementitious layer comprises a cementitious material; and allowing the polymer from the polymer layer to suffuse into the cementitious layer for a period of time to obtain a suffused zone in the cementitious layer such that the suffused zone has a third thickness that is less than half the second thickness.

Abstract: Compositions, systems and methods for use in monitoring an environment or a formation. The compositions can include electrically conductive material that can be used as a sensor. The sensor can have a non-writeable, writeable, and stimulated state. A first signal is used to induce the non-writeable material into a writeable state. In the writeable state, the electrically conductive material has the capacity for actuation in response to an orthogonal signal. In response to the orthogonal signal, the electrically conductive material then undergoes a conformation or shape change. The conformational or shape change induces a strain or actuation that can be used to generate a signal. The stimulated state can be reversible, and in the absence of the orthogonal signal the electrically conductive material may resume its original shape or conformation.

Abstract: Methods for fabricating a multi-material composite structure are described. Methods for fabricating a multi-material composite structure include forming a first colloidal ink solution with a first material matrix, water, and a rheology modifying agent; forming a second colloidal ink solution with a second material matrix, water, and a rheology modifying agent; printing a first layer on a substrate using a first printing nozzle carrying the first colloidal ink solution; printing a second layer on top of the first layer using a second printing nozzle carrying the second colloidal ink solution; forming a 3D structure by printing a plurality of layers including the first layer and the second layer printed in an alternating pattern; and sintering the 3D structure to form the multi-material composite structure.

Abstract: This document relates to shape memory compositions containing a sliding-ring polymer (polyrotaxane) additive and a thermally-curable epoxy resin. The shape memory compositions are able to deform and reform in response to external stimuli. This document also relates to 3D-printed shape memory compositions containing a sliding-ring polymer (polyrotaxane) additive and a thermally-curable epoxy resin.

Abstract: This document relates to epoxy compositions containing a sliding-ring polymer (polyrotaxane) additive and a thermally-curable epoxy resin. The epoxy compositions exhibit increased flexural toughness and impact resistance as compared to the same epoxy composition that does not contain the additive. This document also relates to 3D-printed epoxy compositions containing a sliding-ring polymer (polyrotaxane) additive and a thermally-curable epoxy resin.

Abstract: Methods and systems for cementing a wellbore are described. The methods include forming a slurry including a cement-based matrix, water, a polymer-based additive, and a rheology modifying agent; mixing the slurry to form a printing ink; introducing the slurry and a printer into a wellbore; and forming a cement-based composite structure in the wellbore by printing a plurality of layers using the printing ink.

Abstract: This document relates to sealant compositions containing a sliding-ring polymer (polyrotaxane) additive and a polymeric matrix material. The sealant materials exhibit enhanced mechanical properties as compared to the same sealant composition that does not contain the additive. This document also relates to 3D-printed sealant compositions containing a sliding-ring polymer (polyrotaxane) additive and a polymeric matrix material.

Abstract: Fluid loss control additives for a cement slurry are provided. An exemplary fluid loss control additive includes a copolymer containing 2-acrylamido-2-methylpropane sulfonic acid monomer units and acryloylmorpholine monomer units, and a graft copolymer. The graft copolymer contains a humate and, grafted onto the humate, a side-chain polymer containing at least one of acrylamide monomer units, acryloylmorpholine monomer units, acrylic acid monomer units, and 2-acrylamido-2-methylpropane sulfonic acid monomer units.

Abstract: A reversible gel composition including nanosilica and polyethylene oxide, the nanosilica and polyethylene oxide present at concentrations operable to allow for the reversible gel composition to be a flowable liquid at pH greater than about 8 and operable to allow for the reversible gel composition to be a substantially solid gel at pH less than about 8.

Abstract: A reversible gel composition including nanosilica and polyethylene oxide, the nanosilica and polyethylene oxide present at concentrations operable to allow for the reversible gel composition to be a flowable liquid at pH greater than about 8 and operable to allow for the reversible gel composition to be a substantially solid gel at pH less than about 8.

Abstract: This document relates to methods for preventing or inhibiting the formation of micro-cracks and fractures in the cement of an oil well using cement compositions that contain cross-linked polyrotaxane additives. The cement compositions containing the cross-linked polyrotaxane additives exhibit increased stiffness without suffering a decrease in compressive strength, as compared to the same cement without the cross-linked polyrotaxane additive.

Abstract: A method of using a nanosilica-containing cement in a well cementing operation in a well, the method comprising the steps of pumping a nanosilica-containing cement formulation into the well, wherein the nanosilica-containing cement formulation comprises maltodextrin-coated nanosilica and a cement formulation, where the maltodextrin-coated nanosilica comprises nanosilica particles encapsulated by maltodextrin coating, wherein the pH of the nanosilica-containing cement formulation is between 9 and 14, maintaining a temperature in the well due to a temperature of a formation surrounding the well, wherein the disintegration of the maltodextrin coating is initiated due to the temperature and pH of the nanosilica-containing cement, exposing the nanosilica particles due to the disintegration of the maltodextrin coating from the maltodextrin-coated nanosilica, and reacting the nanosilica particles with the cement formulation such that the transition time is reduced.

Abstract: This document relates to methods for improving the tensile and elastic properties of cement of an oil well using cement compositions that contain sliding-ring polymer additives. The cement compositions containing the sliding-ring polymer additives exhibit increased stiffness while having a minimum impact on compressive strength, as compared to the same cement without the sliding-ring polymer additive.

Abstract: A reversible gel composition including nanosilica and polyethylene oxide, the nanosilica and polyethylene oxide present at concentrations operable to allow for the reversible gel composition to be a flowable liquid at pH greater than about 8 and operable to allow for the reversible gel composition to be a substantially solid gel at pH less than about 8.

Abstract: Systems and methods for testing shear bond strength of cement with a composite sample under downhole conditions form a bonding surface of the sample oriented at an angle between 50 and 70 degrees from a plane perpendicular to a longitudinal axis of the sample. The composite sample is formed by bonding the cement to the sample with the cement in contact with the bonding surface of the sample.

Abstract: This document relates to methods for improving the tensile and elastic properties of cement of an oil well using cement compositions that contain sliding-ring polymer additives. The cement compositions containing the sliding-ring polymer additives exhibit increased stiffness while having a minimum impact on compressive strength, as compared to the same cement without the sliding-ring polymer additive.

Abstract: Compositions, systems and methods for use in monitoring an environment or a formation. The compositions can include electrically conductive material that can be used as a sensor. The sensor can have a non-writeable, writeable, and stimulated state. A first signal is used to induce the non-writeable material into a writeable state. In the writeable state, the electrically conductive material has the capacity for actuation in response to an orthogonal signal. In response to the orthogonal signal, the electrically conductive material then undergoes a conformation or shape change. The conformational or shape change induces a strain or actuation that can be used to generate a signal. The stimulated state can be reversible, and in the absence of the orthogonal signal the electrically conductive material may resume its original shape or conformation.

Abstract: A method of producing a nanosilica-containing cement formulation, the method comprising the steps of mixing an amount of a determinant nanosilica particle and a functional coating; applying a dynamic initiator to trigger a reversible reaction of the functional coating to produce a reversible cage, where the reversible cage surrounds the determinant nanosilica particle to produce an encapsulated nanosilica; and mixing the encapsulated nanosilica and a cement formulation to produce the nanosilica-containing cement formulation