Abstract: An apparatus (11a) for introduction of gas into a wellbore containing production tubing (12a) is provided. The apparatus consists of a conduit (30a) for location at least partly within the production tubing (12a), an inlet (32a) providing communication between the conduit (30a) and a wellbore annulus, and an outlet (34a) providing communication between the conduit and a reservoir (16). The apparatus therefore allows gas to be introduced into reservoir fluids at a distance from introduction of gas into the production tubing, so increasing the effective depth of gas introduction. A method of gas introduction is also described.

Abstract: A flowmeter used to measure the flow rate of a fluid in a conduit includes a flow restrictor insert. The conduit is coupled to an upstream and downsteam conduit portion and includes three pressure measuring stations axially spaced along the conduit wall. The flow restrictor insert includes two cylindrical portions, the second of which has a diameter larger than the first. The flow restrictor insert is positioned in the flowmeter conduit such that the first cylindrical portion is aligned with the second pressure measuring station and the second cylindrical portion is aligned with the third pressure measuring station. When a fluid flows through the conduit, the flow restrictor insert causes the fluid to diverge around the cylindrical portions thereby creating a venturi effect. The fluid flow rate is calculated from the pressure differentials derived from the data measured at the three pressure measuring stations.