Abstract: A method of converting a completed well into a dual completed well that includes selectively pumping a water-based fluid into a first production zone of the completed well, wherein the water-based fluid has a pH of greater than about 5; allowing the water-based fluid to form a continuous, non-flowing water-based gel in the first production zone of the completed well, wherein the water-based gel has a pH of greater than about 5; disposing a layer of cement into the completed well above the water- based gel; perforating a second production zone of the completed well in a location above the layer of cement; drilling through the layer of cement; and breaking the water-based gel located in the first production zone of the completed well, wherein the breaking comprises: exposing the water-based gel to a breaker fluid, wherein the breaker fluid has a pH of greater than about 5 is disclosed.

Abstract: A method of electrically logging subterranean wells using a conductive double emulsion fluid includes a miscible combination of an oleaginous fluid, an emulsifier capable of forming a microemulsion, an emulsifier capable of forming an invert emulsion, and an electrolytic salt. A microemulsion is the continuous phase of an invert emulsion. The electrolytic salt or brine of the salt is present in a concentration sufficient to permit the electrical logging of the subterranean well. The fluid may additionally contain a polar organic solvent and a carbon dioxide buffer. The polar organic solvent may be an oil soluble glycol or glycol ether such as ethylene glycol, diethylene glycol, propylene glycol, polypropylene glycol, and the like.

Abstract: A method of electrically logging subterranean wells using a conductive double emulsion fluid includes a miscible combination of an oleaginous fluid, an emulsifier capable of forming a microemulsion, an emulsifier capable of forming an invert emulsion, and an electrolytic salt. A microemulsion is the continuous phase of an invert emulsion. The electrolytic salt or brine of the salt is present in a concentration sufficient to permit the electrical logging of the subterranean well. The fluid may additionally contain a polar organic solvent and a carbon dioxide buffer. The polar organic solvent may be an oil soluble glycol or glycol ether such as ethylene glycol, diethylene glycol, propylene glycol, polypropylene glycol, and the like.

Abstract: A method of electrically logging subterranean wells using a conductive fluid includes a miscible combination of an oleaginous fluid, a polar organic solvent, an electrolytic salt, and a carbon dioxide buffer. The electrolytic salt or brine of the salt is present in a concentration sufficient to permit the electrical logging of the subterranean well. The polar organic solvent may be an oil soluble glycol or glycol ether such as ethylene glycol, diethylene glycol, propylene glycol, polypropylene glycol, and the like. The electrolytic salt or brine preferably includes a quaternary amine salt having the formula: wherein R is an alkyl having 8 to 18 carbon atoms, R′ is 2 to 6 carbon atoms alkyl group, B is hydrogen, oxyalkyl having 1 to 4 carbon atoms or alkyl having 1 to 4 carbon atoms, A is hydrogen or alkyl with 1 to 4 carbon atoms, x+y=1 to 15, z is 0 to 3, and M is a counter anion; or combinations thereof. The carbon dioxide buffer is preferably a trialkylanol amine.

Abstract: A method of electrically logging subterranean wells using a conductive fluid includes a miscible combination of an oleaginous fluid, a polar organic solvent, an electrolytic salt, and a carbon dioxide buffer. The electrolytic salt or brine of the salt is present in a concentration sufficient to permit the electrical logging of the subterranean well. The polar organic solvent may be an oil soluble glycol or glycol ether such as ethylene glycol, diethylene glycol, propylene glycol, polypropylene glycol, and the like.