Abstract: A method for obtaining a fluid sample downhole that has at least a target fluid and an undesirable fluid may include receiving the fluid sample into a sample tank positioned that has a main chamber and isolating at least a portion of the undesirable fluid from the target fluid in the main chamber. A related apparatus may include a conveyance device configured to be conveyed along a borehole and a fluid sampling tool positioned along the conveyance device. The conveyance device may include a probe receiving the fluid sample from a formation; a pump drawing the fluid sample through the probe; and at least one sample tank receiving the fluid sample from the pump. The sample tank may include a main chamber receiving the fluid sample and an isolation volume isolating at least a portion of the undesirable fluid from the target fluid in the main chamber.

Abstract: Clean-up additive compositions may be used to enhance the clean-up of VES-gelled aqueous fluids in a wide range of applications and VES fluid compositions, including use of an internal breaker system. The compositions are microemulsions that may include, but not necessarily be limited to, at least one viscosity reducing agent, at least one solubilizing agent, at least one desorption agent and at least one water wetting agent. One non-limiting embodiment of a specific microemulsion includes an unsaturated fatty acid oil, a glycol, a sorbitan ester/ethoxylated sorbitan ester mixture, and an alkyl sulfonate. Microemulsions may perform one or more of the following functions: keeping the reservoir water wet; keeping surface tension reduction low; demulsifying reservoir crude oils and aqueous VES fluids; dispersing and solubilizing the by-products generated when breaking the VES gel; and/or limiting the amount of VES residue on reservoir minerals.

Abstract: An inducer pump located internally in an electrical submersible pump motor enhances lubricant circulation within the motor. The inducer is located at the lower end of the shaft within a shaft bore. The inducer has a rod and a helical flight rigidly mounted to the rod. The inducer rotates in unison with the motor, pumping lubricant from a lower lubricant chamber upward through the shaft bore.