Abstract: Radioactive particles are provided for use in tracing the flow path in or near a well of fluids injected into the well. The particles include an element which can be made radioactive by bombardment with neutrons and a material to encapsulate the element. The encapsulant is preferably an organic polymer having a high softening temperature. The particles may be injected into a well in treating fluids and their location may be later determined by gamma ray logging of the well.

Abstract: An insulative threaded connection is provided for metal tubulars to be placed in wells or for other metal pipe. The connection contains a coating of plastic having a selected thickness which is applied to the surface of the threads of a tubular to be mated with another joint of tubular. The plastic contains particles at a selected loading such that the particles support load between the mated threaded joints. Metal is removed from the mating threads, the thickness of the metal removed being about the same as the thickness of the plastic coating. The coating may be applied to the pin end or the box end of connections. The box end may be a coupling or an integral threaded area. The insulative threaded connection is used in tubulars for improved transmission of electromagnetic signals to or from wells.

Abstract: A gamma ray spectral tool is provided that can be used in slick line systems. The tool includes a battery, a controller, and a memory. In operation, the tool compresses data from the spectral detector for storage in the memory, allowing for long runs without the memory overflowing. Further, a controller latches the self-adjusting stabilization feature of the spectral detector when gamma ray intensity exceeds a predetermined threshold, preventing erroneous "stabilization" by the stabilization feature of the spectral detector.

Abstract: There is provided radioactive particles having a ceramic matrix and an element which can be bombarded with neutrons to produce a gamma ray-emitting isotope. The particles are manufactured by mixing the ceramic components and the element, forming particles, sintering the particles, and the particles are subsequently made radioactive by bombardment with neutrons. Particles injected into wells or flow apparatus are traced by adding the radioactive particles and detecting the radioactive particles with gamma ray-sensitive instruments. Particles containing different elements are detected by spectral analysis of gamma rays.

Abstract: There is provided radioactive particles having a ceramic matrix and an element which can be bombarded with neutrons to produce a gamma ray-emitting isotope. The particles are manufactured by mixing the ceramic components and the element, forming particles, sintering the particles, and the particles are subsequently made radioactive by bombardment with neutrons. Particles injected into wells or flow apparatus are traced by adding the radioactive particles and detecting the radioactive particles with gamma ray-sensitive instruments. Particles containing different elements are detected by spectral analysis of gamma rays.

Abstract: The present disclosure is directed to a method and apparatus for controllably injection a radioactive isotope tracer fluid into a fracture fluid, a manifold or mud flow line connected to a well. It is best used in measuring well stimulation procedures based on injection of tracer isotopes so that stimulation performance data can be obtained by gamma ray spectroscopic measuring instruments lowered in the well borehole after fracture. The present apparatus utilizes a tank supply of tracer fluid connected through a pump into the mud line wherein the pump drives a tachometer, and utilizes a CPU to respond to pumping rate measurements and adjust the pumped rate of the tracer fluid.