Abstract: Apparatus for measuring multiphase fluid flows comprising first and second sections each comprising a flow passage having means for making a dynamic pressure measurement on the multiphase fluid flow therethrough, the geometry of the first and second sections differing so as to affect a relationship between void fraction and velocity for the phases in a known manner. The difference in geometry between the two sections can be in the area of the flow passages or in the direction of flow relation to gravity. A method of measuring multiphase flows comprising the steps of:a) directing the flow through a first flow passage including means for making a dynamic pressure measurement;b) measuring a pressure drop across said means;c) directing the flow through a second flow passage including means for making a dynamic pressure measurement;d) measuring a pressure drop across said means; ande) calculating the composition and flow rates of the phases from the measured pressure drops.

Abstract: The invention relates to measuring the bubble point of oil down a well drilled into an underground formation. The pressure is measured by an apparatus lowered down the well. The apparatus comprises a chamber (2) in which a small quantity of oil is confined in a volume which is variable by a needle (3) having portions of different diameters (3a, 3b) capable of being inserted to a greater or lesser extent into the chamber (2) under drive from a motor (7). Values of pressure inside the chamber and of chamber volume are respectively measured by a manometer (11) and by a displacement sensor (12) connected to the needle (3) and are transmitted to the surface.

Abstract: The present invention relates to a method of and apparatus for converting an oil well with natural effluent rise to one with gas-lift of the effluent column, wherein the oil well has a nipple in the production tube provided with a stop-groove and smooth bearing surfaces between which a hydraulic control line comes out. For conversion an inner tube is lowered inside the production tube, the inner tube being provided with a locking system for locking the inner tube to the nipple, and with a safety valve assembly capable of closing both the passage inside the inner tube and the annular passage between the latter and the production tube, under the action of a control fluid supplied by the control line which opens between two seals on the inner tube and which bear against the smooth bearing surfaces when locking is effected.

Abstract: In accordance with an illustrative embodiment of the present invention, a hollow mandrel mounted in a production string has an eccentrically disposed, lateral recess adapted to receive a measuring instrument. A plug-in contact assembly is located at the lower end of the recess and is connected to an electric cable which is fixed to the outside of the production string. The measuring instrument includes a receptacle assembly on its lower end which is fitted onto the contact assembly during emplacement of the instrument in the recess, thereby to provide in combination with the cable an insulated electric connection between the measuring instrument and the surface. The measuring instrument can be placed into, or removed from, the recess as desired, for example by means of conventional running and pulling tools that are lowered into the production string at the end of a wireline.

Abstract: In accordance with an illustrative embodiment of the present invention, a hollow mandrel mounted in a production string has an eccentrically disposed, lateral recess adapted to receive a measuring instrument. A plug-in contact assembly is located at the lower end of the recess and is connected to an electric cable which is fixed to the outside of the production string. The measuring instrument includes a receptacle assembly on its lower end which is fitted onto the contact assembly during emplacement of the instrument in the recess, thereby to provide in combination with the cable an insulated electric connection between the measuring instrument and the surface. The measuring instrument can be placed into, or removed from, the recess as desired, for example by means of conventional running and pulling tools that are lowered into the production string at the end of a wireline.