Abstract: Systems and methods for determining annular fill material using resistivity measurements are provided. In one example, a method is provided. The method may include placing a downhole tool into a cased well. The well may include an annulus located between a casing and a formation. The method may also include determining, by the downhole tool, resistivity measurements associated with portions of the well. Furthermore, the method may include identifying, by a computer, based at least in part on the resistivity measurements, the presence of annular fill materials in the well. Additionally, the method may include determining, by the computer based at least in part on the resistivity measurements, respective locations of the annular fill materials in the well.

Abstract: This invention relates to methods for servicing subterranean wells, in particular, fluid compositions and methods for remedial operations during which the fluid compositions are pumped into a wellbore and make contact with well cements placed during primary cementing or previous remedial cementing operations.

Abstract: Compositions that swell on contact with water contain a non-swellable thermoplastic or thermoset polymer and a swellable inorganic compound. In particular, the compositions are suitable for use in subterranean wells such as those used in the oil and gas industry. The polymer may be polypropylene and the inorganic compound may be magnesium oxide.

Abstract: Methods for treating and restoring zonal isolation in a subterranean well involve the use of a well treatment tool that may drill one or more holes in casing and inject a treatment fluid that may seal cracks or fissures in the cement sheath behind the casing. Microannuli may also be sealed. The treatment fluids may be solids free or in the form of suspensions containing solids having a particle size between 1 nm and 100 nm.

Abstract: Incorporation of carbonaceous materials in a cement slurry increases the linear thermal-expansion coefficient of the set cement. When placed in a subterranean well having at least one casing string, cement sheaths with linear thermal-expansion coefficients similar to that of the casing will be subjected to lower compressive and tensile stresses during downhole-temperature changes. Such cement slurries are particularly advantageous in the context of thermal-recovery wells.

Abstract: Methods for cementing a subterranean well comprise installing a casing string into a borehole, wherein the casing string comprises a metal having a coefficient of thermal expansion (CTE) lower than about 6×10?6/° C. A cement sheath is then placed between the exterior surface of the casing string and the formation wall. The low-CTE metal may reduce casing shrinkage when the well temperature falls during stimulation treatments, cyclic steam injection or when the well temperature reaches equilibrium at the top of a long casing string.

Abstract: A water absorbing composition includes a particle having a core of a water-swelling material. A coating substantially surrounds the core that temporarily prevents contact of water with the water-swelling material. The coating may be formed from a layer of water degradable material or a non-water-degradable, non-water absorbent encapsulating layer. A quantity of particles including delayed water-swelling particles formed at least in part from a water-swelling material and, optionally, non-water-swelling particles of the same or different size distributions can be used in treating a formation penetrated by a wellbore. A slurry of the particles is formed with a carrier fluid. The slurry of particles is introduced into the wellbore of the formation to facilitate treatment.

Abstract: Systems and methods for determining annular fill material using resistivity measurements are provided. In one example, a method is provided. The method may include placing a downhole tool into a cased well. The well may include an annulus located between a casing and a formation. The method may also include determining, by the downhole tool, resistivity measurements associated with portions of the well. Furthermore, the method may include identifying, by a computer, based at least in part on the resistivity measurements, the presence of annular fill materials in the well. Additionally, the method may include determining, by the computer based at least in part on the resistivity measurements, respective locations of the annular fill materials in the well.

Abstract: Thermal recovery wells, geothermal wells and deep hot wells may involve the application of heat to the cement sheath and well casing at some time after the cement has set. Such heating may subject the cement sheath to mechanical burdens that may lead to failure. Such burdens may be lessened if the linear thermal coefficient of expansion is variable and approximates that of the well casing. A variable linear thermal coefficient of expansion may be achieved by incorporating blast furnace slag, silica fume, fly ash or a combination thereof in the cement blend.

Abstract: Compositions that swell on contact with water contain a non-swellable thermoplastic or thermoset polymer and a swellable inorganic compound. In particular, the compositions are suitable for use in subterranean wells such as those used in the oil and gas industry. The polymer may be polypropylene and the inorganic compound may be magnesium oxide.

Abstract: Well cement compositions comprise water, an inorganic cement and one or more fillers having a thermal expansion coefficient (CTE) that is lower than about 3×10?6/° C. The presence of low-CTE fillers may reduce cement-sheath shrinkage when the well temperature falls during stimulation treatments, cyclic steam injection or when the well temperature reaches equilibrium at the top of a long casing string.

Abstract: This invention relates to methods for servicing subterranean wells, in particular, fluid compositions and methods for remedial operations during which the fluid compositions are pumped into a wellbore and make contact with well cements placed during primary cementing or previous remedial cementing operations.

Abstract: Treatment fluids and methods for treating a subterranean formation include introducing a treatment fluid into a subterranean formation, the treatment fluid containing a nanocrystalline cellulose. The treatment fluid may be a fracturing fluid, well control fluid, well kill fluid, well cementing fluid, acid fracturing fluid, acid diverting fluid, a stimulation fluid, a sand control fluid, a completion fluid, a wellbore consolidation fluid, a remediation treatment fluid, a spacer fluid, a drilling fluid, a frac-packing fluid, water conformance fluid or a gravel packing fluid.

Abstract: Cement compositions comprising an inorganic cement, water, polymer particles and a water immiscible fluid are useful for reducing the torque necessary to rotate casing during a cementing operation. Such casing movement promotes efficient removal of drilling fluid from the annulus between the casing and the formation or the casing and another casing string. The compositions are particularly useful for cementing operations involving deviated and horizontal wells.

Abstract: Methods for sealing voids and cracks in subterranean-formation rock that contains carbonate minerals, thereby minimizing or stopping fluid flow between the formation rock and the wellbore of a subterranean well, comprise pumping a solution of one or more lattices that contains at least one carboxylated monomer down a well during drilling and allowing it to enter voids (e.g., pores, fractures, vugs and caverns) in the carbonate-containing formation. The solution reacts with divalent cations liberated by the carbonates and forms a plug.

Abstract: Methods for improving the bonding of a cement sheath to a tubular body in a subterranean well involve anchoring elements mounted on the outside surface of the tubular body—in the annular space between the tubular body and the borehole wall. The cement contains an expansive agent that causes the cement to expand after it sets. The anchoring elements are mounted such that an angle exists between the elements and the tubular-body surface, thereby providing resistance to cement sheath movement away from the tubular-body surface.

Abstract: Methods for cementing a subterranean well comprise installing a casing string into a borehole, wherein the casing string comprises a metal having a coefficient of thermal expansion (CTE) lower than about 6×10?6/° C. A cement sheath is then placed between the exterior surface of the casing string and the formation wall. The low-CTE metal may reduce casing shrinkage when the well temperature falls during stimulation treatments, cyclic steam injection or when the well temperature reaches equilibrium at the top of a long casing string.

Abstract: Well cement compositions comprise water, an inorganic cement and one or more fillers having a thermal expansion coefficient (CTE) that is lower than about 3×10?6/° C. The presence of low-CTE fillers may reduce cement-sheath shrinkage when the well temperature falls during stimulation treatments, cyclic steam injection or when the well temperature reaches equilibrium at the top of a long casing string.

Abstract: Process fluids comprising more than 1 wt % polyacrylamide and a non-metallic crosslinker may be used to control lost circulation in subterranean wells. The process fluid is placed into a subterranean lost-circulation zone and allowed to crosslink, thereby forming a gel barrier that limits further flow of process fluid into the zone. The non-metallic crosslinker may preferably comprise one or more polylactams. A pH-adjusting agent may also be incorporated into the process fluid.

Abstract: A method of and apparatus for treating a zone in a well is disclosed. A tube that is permeable to a material is inserted into a wellbore, creating an annulus inside the wellbore. Two zones—the annular region and the formation surrounding the wellbore—may be treated. The method comprises the following steps. (1) A setting section surrounded by a sleeve is placed inside the tube near the zone to treat, the sleeve being expandable and impermeable to the material. (2) The sleeve is inflated inside the tube near the zone to treat, ensuring that a first zone of the tube is impermeable to the material, but leaving a second zone permeable to the material. (3) A treatment fluid is pumped to the zone to treat, the treatment fluid passing into the annulus via the second zone. (4) The zone to treat is treated with the treatment fluid.