Abstract: An oil mining configuration primarily intended for use as a production drift for the recovery of petroleum from an overlying, oil bearing formation by gravity drainage. The configuration is in the general shape of a lollipop when viewed from above and has a stem portion and an annular head portion. The stem portion extends from a first location adjacent a main drift to a second location. The annular head portion extends from the second location about a vertical axis to a third location and on around to the second location to complete the lollipop shape. Production wells are drilled upwardly from the lollipop drift and the produced oil as well as gas and water are collected in tanks in the head portion and pumped up a service well extending from the head portion to the surface. Two methods of forming the lollipop drift are disclosed as are details of its design and operation including air flow and accidental spill recovery.

Abstract: A hydraulic technique for logging well holes particularly in oil mining environments where the well holes extend upwardly from mining drifts. In the technique, the logging tool is initially positioned within the well hole in a fluid-tight, sealing engagement with the well hole. The tool is connected by a flexible cable to conventional logging instruments located in the drift and to raise the tool, fluid under a first pressure is supplied below the tool within the well hole. Once raised to the desired height within the well hole, the cable is drawn downwardly raising the pressure in the fluid below the tool to a second pressure. Through a disclosed arrangement including a back pressure regulator, the pressure below the tool is maintained at the second pressure as the cable continues to be drawn downwardly.