Abstract: Method and apparatus to stabilize a columnar platform for deepwater offshore applications. An added mass stabilizer system is utilized to control first order heave, pitch, roll, surge and sway motions of the floating platform. The stabilizer is suspended beneath the platform by a set of tendons a sufficient distance to (1) enter a quiescent zone beneath the action of waves and currents, (2) provide a sufficiently long movement arm to resist pitch and roll torquing, and (3) incorporate sufficient flexibility into the suspension system to avoid shock loads. The stabilizer is sized to (a) provide sufficient submerged weight to maintain the tendons in constant tension and, (b) create adequate added mass (actual stabilizer weight plus mass of water moved by the stabilizer) to provide the desired control of first order motions. A secondary mooring system such as a spring-buoy mooring or dynamic positioning system can be provided to control drift produced by higher order motions and first order yaw.

Abstract: A radioactive logging method for evaluating a wellbore and its surrounding formation in which gamma-ray emitting nuclides may be naturally present. A radioactive tracer is injected into the formation. The tracer emits gamma rays at at least one energy at which substantially none of the naturally present elements emit gamma rays. The wellbore is traversed with a gamma-ray detection system which is tuned to detect gamma rays at the one energy level of the tracer, thus providing a profile of tracer distribution in the formation.

Abstract: A subterranean formation is penetrated by a borehole. The formation is fractured and propped with a slurry capable of maintaining a thermit reaction. The slurry is ignited. Upon cooling, a solid metal conductor fin network from the bore into the formation is formed in the fracture system. Energy is transferred between a locus in the borehole and the formation by the network.