Abstract: An injector head for feeding a tool string support member downhole is described. The injector head includes a first gripping device and a second gripping device. The first and second gripping devices are adapted to grip a tool string support member passing through an injector head passageway. The injector head further includes an actuator movable between a first position and a second position wherein, movement of the actuator between the first and second positions moves at least a portion of both of the first and second gripping devices towards or away from a passageway longitudinal axis.

Abstract: An injector head for feeding a tool string support member downhole is described. The injector head includes a first gripping device and a second gripping device. The first and second gripping devices are adapted to grip a tool string support member passing through an injector head passageway. The injector head further includes an actuator movable between a first position and a second position wherein, movement of the actuator between the first and second positions moves at least a portion of both of the first and second gripping devices towards or away from a passageway longitudinal axis.

Abstract: A nuclear magnetic resonance method and apparatus are disclosed. A sample is provided where the nuclear spin Hamiltonian operator of the component molecules of the sample possess one or more symmetry operations. A quasi equilibrium nuclear spin ensemble state in a sample is created. The quasi equilibrium nuclear spin ensemble state includes at least two manifolds of spin states which transform differently under the symmetry operations of the Hamiltonian and the manifolds having different mean nuclear spin populations. The quasi equilibrium nuclear spin ensemble state is allowed to remain for a time of equal to or substantially greater than 3T1, where T1 is the spin lattice relaxation time. The symmetry operation of the Hamiltonian is broken. A sequence of magnetic fields is applied to generate a nuclear magnetic resonance signal from the sample. The nuclear magnetic resonance signal is detected.