Abstract: A method of cementing a well using a cementing spacer. The method includes pumping a drilling fluid into a well. A cementing spacer is then pumped into the well to serve as a buffer between the drilling fluid and a cement. The cementing spacer includes substantially unviscosified water and a weighting agent. Cement is then pumped into the well to displace the cementing spacer and the drilling fluid to complete the cementing of the well.

Abstract: An improved method of monitoring the setting of a settable liquid-containing material is provided. The compressibility of one or more fluids including the settable material is monitored at periodic intervals during the setting process. As the material sets, its compressibility is lowered, and the overall fluid compressibility is reduced. When the settable material hardens completely, its compressibility approaches zero and the overall fluid compressibility levels off. The method is especially useful for monitoring the setting of cement in the annulus of a well bore, and for determining when the cement is fully set.

Abstract: Cement plugs are positively placed in a wellbore by placement of a bridge plug immediately beneath the depth where the plug is intended and release of a seal allowing flow of cement slurry from a slurry containment tube as the tube is withdrawn to cause a positive piston-like displacement of the fluid in the wellbore.

Abstract: Cement bonding and bond logs in wells are significantly improved by imparting random or periodic, pulsating, oscillating or vibrating pressure to the fluids present during all stages of a cementing operation. The effect is to eliminate gelation of the fluids to improve cement placement and to enable consolidation of the cement slurry. The pressure pulses can also be detected to monitor the condition of the setting slurry.

Abstract: An apparatus and a method for ascertaining the relative amount of two or more phases present in a multiphase flow, such as produced petroleum, through a pipe. Multiphase flow is temporarily diverted into a test section. Normal flow is then restored with fluids trapped in the test pipe. One or more floats of proper densities inside the test pipe are allowed to float to and stabilize at positions representative of the phase interfaces. An electromagnetic, radioactive, acoustic, or other sensor is used from outside the test pipe to locate the interfaces as indicated by the position of the floats. The relative amount of the various phases is then calculated. In an alternative embodiment, the velocity of a piston located inside the test section is also measured to give the total flow rate of the multiphase flow. The total volumetric flow rate, along with the relative phase amounts gives the absolute volumetric phase flow rates.

Abstract: Apparatus situated in a borehole traversing an earth formation is protected from closure of the borehole by being encased in an inflatable device. Surface equipment inflates and maintains the inflatable device at a sufficient pressure so as to prevent the earth formation from closing in and contacting the apparatus.