Abstract: In a method of treating a subterranean formation, a well treatment composition comprising a dispersion of a water-in-oil emulsion in an aqueous medium is injected into the formation. The water-in-oil emulsion has an internal aqueous phase and an external phase containing a liquid hydrocarbon and a surfactant soluble in the hydrocarbon. The compositions can be designed to perform various well treatment applications including hydraulic fracturing and acidizing and can also be used to encapsulate or to transport well treatment materials and chemicals into the wellbore or formation. Treatment methods may also employ dispersions of a reactive simple or multiple emulsion. The distinct phases of the compositions may be selected to form treatment solutions upon mixing. Thus, improved acidizing may be achieved through an in situ reaction format.

Abstract: This relates to testing the impedance and common mode rejection characteristics of multi-channel seismic data gathering apparatuses. The apparatus embodying the invention includes a signal recording and computing system with a plurality of input channels; a plurality of geophone channels, each with a high wire and a low wire; a high bus and a low bus; a plurality of reference impedances; and a signal generator with two output terminals. Each geophone channel comprises one or more geophones which are connected by the wires to the input channels of the recording and computing system. Additionally, the high wire of each channel is connected through a reference impedance to the high bus and the low wire of each channel is connected through a reference impedance to the low bus. The apparatus also includes switching means for selectively controlling the connections between the buses, the generator and ground.