Abstract: A sensor carried by a pipe string measures a downhole condition. After a delay, a signal is transmitted to the surface. The delay is proportional to the measurement and can be measured in time, in revolutions of the pipe string, or in the volume of fluid pumped during the delay.

Abstract: The device disclosed includes a housing which can be moved through the bore hole and anchored in the desired location for drilling a lateral hole. Located in the housing is a drill string guide or conductor having a bendable lower end. The conductor is movable to a position where its lower end is either inherently or forceably bent so that it provides a curved path leading toward the side wall of the bore hole. The conductor guides a drill string extending through the conductor to cause the drill string to drill a lateral hole in the side wall of the well bore. The drill string and conductor can be retracted into the housing when the lateral hole has been drilled, or a portion of the drill string may be left in the lateral hole as a drain pipe.

Abstract: The apparatus disclosed includes an elongated reinforcing member with stress anchors attached to each end for embedding in a body of hardenable material, such as concrete, when the material is cast into the desired shape for the structural member. The apparatus includes a member containing potential energy. After the material has hardened, the potential energy is released to place the material between the stress anchors in compression to prestress the structural member before it is placed in service.