Abstract: According to an embodiment, an invert emulsion drilling fluid comprises: an external phase, wherein the external phase of the drilling fluid comprises a hydrocarbon liquid; an internal phase, wherein the internal phase of the drilling fluid comprises water; and a surfactant, wherein the surfactant: (A) comprises a hydrophobic tail group having a carbon chain length greater than or equal to 16; (B) has a boiling point greater than or equal to 400° F. (204.4° C.); and (C) is in at least a sufficient concentration such that the surfactant spontaneously forms reverse-micelles. According to another embodiment, a method of using the invert emulsion drilling fluid comprises: introducing the drilling fluid into a well.

Abstract: According to an embodiment, an invert emulsion drilling fluid comprises: an external phase, wherein the external phase of the drilling fluid comprises a hydrocarbon liquid; an internal phase, wherein the internal phase of the drilling fluid comprises water; and a surfactant, wherein the surfactant: (A) comprises a hydrophobic tail group having a carbon chain length greater than or equal to 16; (B) has a boiling point greater than or equal to 400° F. (204.4° C.); and (C) is in at least a sufficient concentration such that the surfactant spontaneously forms reverse-micelles. According to another embodiment, a method of using the invert emulsion drilling fluid comprises: introducing the drilling fluid into a well.

Abstract: A lubricant for use in silicic acid muds and other drilling fluids comprising silicate or silica species is disclosed. The lubricant significantly improves the lubricity of the fluid. A method of drilling a wellbore in a subterranean formation employing the lubricant is also disclosed. A preferred lubricant of the invention comprises about 80 volume percent 2-octyldodecanol and about 20 volume percent alkylglucoside. The alkylglucoside is preferably comprised of 2-ethylhexylglucoside or a mixture of alkylglucosides having more than about 10 carbon atoms in the alkyl chain.

Abstract: A method is provided for reducing loss of drilling fluid and for stabilizing a wellbore during drilling through depleted sands in a subterranean formation comprising depleted sands. The method comprises introducing into said wellbore and into said depleted sands an aqueous fluid comprising silicate or siliconate and resilient graphitic carbon in an amount effective at substantially plugging pores in said depleted sands.

Abstract: A method is provided for reducing loss of drilling fluid and for stabilizing a wellbore during drilling through depleted sands in a subterranean formation comprising depleted sands. The method comprises introducing into said wellbore and into said depleted sands an aqueous fluid comprising silicate or siliconate and resilient graphitic carbon in an amount effective at substantially plugging pores in said depleted sands.

Abstract: Well drilling and servicing fluids for use in producing formations and methods of removing filter cake therefrom are provided. The methods basically comprise using a drilling or servicing fluid comprised of water, a density increasing water soluble salt, a fluid loss control agent, a hydratable polymer solid suspending agent and a particulate solid bridging agent which is soluble in an aqueous ammonium salt solution. Thereafter, the filter cake deposited by the drilling or servicing fluid is contacted with a clean-up solution comprised of water and an ammonium salt for a period of time such that the bridging agent is dissolved thereby.

Abstract: A lubricant for use in silicic acid muds and other drilling fluids comprising silicate or silica species is disclosed. The lubricant significantly improves the lubricity of the fluid. A method of drilling a wellbore in a subterranean formation employing the lubricant is also disclosed. A preferred lubricant of the invention comprises about 80 volume percent 2-octyldodecanol and about 20 volume percent alkylglucoside. The alkylglucoside is preferably comprised of 2-ethylhexylglucoside or a mixture of alkylglucosides having more than about 10 carbon atoms in the alkyl chain.

Abstract: Well drilling and servicing fluids for use in producing formations and methods of removing filter cake therefrom are provided. The methods basically comprise using a drilling or servicing fluid comprised of water, a density increasing water soluble salt, a fluid loss control agent, a hydratable polymer solid suspending agent and a particulate solid bridging agent which is soluble in an aqueous ammonium salt solution. Thereafter, the filter cake deposited by the drilling or servicing fluid is contacted with a clean-up solution comprised of water and an ammonium salt for a period of time such that the bridging agent is dissolved thereby.

Abstract: Well drilling and servicing fluids for use in producing formations and methods of removing filter cake therefrom are provided. The methods basically comprise using a drilling or servicing fluid comprised of water, a density increasing water soluble salt, a fluid loss control agent, a hydratable polymer solid suspending agent and a particulate solid bridging agent which is soluble in an aqueous ammonium salt solution. Thereafter, the filter cake deposited by the drilling or servicing fluid is contacted with a clean-up solution comprised of water and an ammonium salt for a period of time such that the bridging agent is dissolved thereby.

Abstract: A water-based drilling fluid for use in shale formations having a given average pore size has solutes dissolved therein sized so as to allow the pores of the shale formations to at least partially restrict the solutes. For purposes of enhancing the restriction of the solutes by the shale pores, the dissolved solutes may have different radii. Additional solutes, preferably lower molecular weight salts, are dissolved in the drilling fluid to lower the activity of the water in the water-based drilling fluid.The same combination of additives, a first additive of dissolved molecular solutes sized to at least partially block a shale pore space and a second additive of dissolved molecular solutes selected to lower the water activity, are combined in a water-based carrier fluid and used in earth boreholes surrounded by shale formations as either a spotting fluid, or as a lubricant, or as a shale formation strengthener or as a completion fluid.

Abstract: A method and combination of materials for freeing stuck pipe involves first the spotting of a clear brine, preferably calcium chloride, calcium bromide or zinc bromide, or mixtures thereof, for a given period of time, preferably at least about 8 hours, in the stuck region of the pipe, followed by the spotting of a spotting agent selected from wetting agents, surfactants, lubricants, or mixtures thereof, in the region of the stuck pipe.

Abstract: A method and combination of materials for freeing stuck pipe involves first the spotting of a clear brine, preferably calcium chloride, calcium bromide or zinc bromide, or mixtures thereof, for a given period of time, preferably at least about 8 hours, in the stuck region of the pipe, followed by the spotting of a spotting agent selected from wetting agents, surfactants, lubricants, or mixtures thereof, in the stuck region of the pipe.

Abstract: An apparatus for testing fluid loss characteristics of a test fluid such as drilling mud under static or dynamic conditions, the apparatus having a filter medium cell which has a generally vertically disposed cylindrical wall, the apparatus further including a first chamber which is in open communication with the inner surface of the cylindrical wall and a second chamber which is in communication with the outer surface of the cylindrical wall, there being a generally vertically disposed rotatable shaft which is received internally of the cylindrical wall, the shaft being driven by a motor or the like, the apparatus being capable of providing a differential pressure across the cylindrical wall such that fluid will flow from the first chamber to the second chamber in response to the differential pressure and the liquid passing into the second chamber can be suitably measured and used to calculate fluid loss rate of the test fluid.