Abstract: A first temperature sensor is carried by the drill pipe on a radially extensible arm for positioning the sensor at or near the face of the well bore for measuring the true temperature of the face. A second temperature sensor at an intermediate position on the arm measures the temperature of the drilling fluid near the location of the first sensor. The first sensor takes a plurality of readings over a predetermined period of time to detect changes in surface temperature. Both sensors transmit their measurements to a microprocessor, which employs the laws of multidimensional and transient heat transfer by conduction to calculate the true formation temperature.

Abstract: A first temperature sensor is carried by the drill pipe on a radially extensible arm for positioning the sensor at or near the face of the well bore for measuring the true temperature of the face. A second temperature sensor at an intermediate position on the arm measures the temperature of the drilling fluid near the location of the first sensor. The first sensor takes a plurality of readings over a predetermined period of time to detect changes in surface temperature. Both sensors transmit their measurements to a microprocessor, which employs the laws of multidimensional and transient heat transfer by conduction to calculate the true formation temperature.

Abstract: A noncondensable gas such as H.sub.2 S is removed from a condensable vapor in a two-sided heat exchanger employing multi-stage condensation or counter current flow, and the condensate so formed is employed as a cooling medium on the opposite side of the heat exchanger while itself being vaporized into a clean gas. In multi-stage condensation, a portion of the condensate is formed at each stage of a system and the condensate so formed does not progress to the next stage. In a counter current flow system, the condensate is at least temporarily retained in the condensing area so that additional noncondensable gas may be stripped from the condensate by the gaseous mixture of noncondensable gas and condensable vapor. Before condensate from either type of system is employed as a coolant, it is subjected to flash evaporation.

Abstract: A heat exchanger used in the multi-stage flash distillation process is provided at the cool end with a gas injection device that creates two-phase flow within the tube side of the heat exchanger. At the hot end, the two-phase flow is degasified and the gas recycled through the cool end. Alternatively, where multiple heat exchanger modules are used, the two-phase flow from each tube in the first exchanger is directly routed to a tube of the second exchanger, or the two-phase flow from the first exchanger is separated and the individual phases are recombined in the entrance of the second exchanger. A gas injection device is used for creation of the two-phase flow, and this employs a gas chamber with gas supply tubes running into the liquid inlet ends of the heat exchanger tubes to introduce the gas uniformly into each tube.

Abstract: A noncondensable gas such as H.sub.2 S is removed from a condensable vapor in a two-sided heat exchanger employing multi-stage condensation or counter current flow, and the condensate so formed is employed as a cooling medium on the opposite side of the heat exchanger while itself being vaporized into a clean gas. In multi-stage condensation, a portion of the condensate is formed at each stage of a system and the condensate so formed does not progress to the next stage. In a counter current flow system, the condensate is at least temporarily retained in the condensing area so that additional noncondensable gas may be stripped from the condensate by the gaseous mixture of noncondensable gas and condensable vapor. Before condensate from either type of system is employed as a coolant, it is subjected to flash evaporation.