At present, majority of domestic oilfields are exploited to intermediate and later periods and water content in petroleum wells are generally higher and some individual plots contain over 98% of water. If adopting current exploitation process, it will be expensive, energy-consuming and less efficient. The quantity of reinjection in ground sewage treatment has been gradually increasing, expenses for sewage treatment have been gradually increasing and environmental protection has been facing a tough situation. In order to solve current situation, it is proposed to take the measure of realizing petroleum exploitation and water injection simultaneously (hereinafter referred to as injection-recovery in the same well) in the same petroleum well.
The injection-recovery in the same well unit underground part is generally composed of screw pump petroleum exploitation lifting system and electric pump inversion reinjection system.