Gas Lift Well Testing Technology with Small Diameter Tubing in Offshore Oil and Gas Fields

摘要

The proportion of 'three low' (low porosity, low permeability and low saturation) oil and gas fields in offshore has been growing. Test technology for the wells on an off shore platform is becoming demanding. The lifting method must meet requirements such as uncertainty of pump depth (unknown formation pressure), accurate control of the production pressure difference (to prevent formation collapse), short operation time (high costs for offshore operations) and so on. The test technology such as conventional gas lift, screw pump and submersible electric pump etc. can not meet the rapid, efficient and economic testing requirements on an offshore platform due to their respective disadvantages. In this paper, we proposed a new well testing technology for the 'three low 'oil and gas fields in offshore by injecting gas through the annulus between the drill pipe and the small diameter tubing. Furthermore we also optimized the structures of the gas lift valve and mandrel and developed the supporting software. Application results show that the supporting tools work well, the down-well test can be conducted smoothly and the practicability of the gas lift well test technology with small diameter tubing was verified successfully.