Project Title:Efficient Extraction Technology with Rodless Lifting for Horizontal Well of Shale Oil Platform

Participating Enterprises: CNPC Changqing Oilfield Shale Oil Development Branch, Oil and Gas Technology Research Institute of Changqing Oilfield Branch

Award Received: Technological Innovation Award

Achievement Level: International Advanced Level

Project Number: ECF-2025-SET-1011

Main Participants: Huang Zhanwei, Ma Hongxing, Dang Yongchao, Wang Xiaorui, Liu Huanyu, Fan Song, Yue Yuanzhou, Hu Sujuan, Tian Weidong, Zhang Lei, Wang Yihang, Zhang Xin, Liu Zhiyong, Chai Xiaoyong, Zhong Jianwei

Expert Review Comments:
International advanced level. This project addresses key challenges in lifting and production for large-platform, long horizontal shale oil wells—such as rod and tubing wear, complex wellbore conditions, and fluctuating liquid volumes. It innovatively developed a “two-stage rodless lifting + dynamic balanced oil production” technology system, featuring an electric submersible screw pump (ESPM) system and a “five-in-one” wellbore integrated control process to achieve efficient, safe, intelligent, and green production operations.
Through automatic production parameter acquisition and online condition diagnosis, the technology realizes intelligent pressure balancing combined with photovoltaic power supply, forming an intelligent rodless oil recovery system suitable for platform-based shale oil development.
The technology has been applied in over one hundred wells across the Changqing Oilfield, significantly enhancing recovery efficiency and operational stability, with remarkable economic and social benefits. It demonstrates broad prospects for industrialization and widespread application.

Main Innovations:

1. Two-Stage Lifting Technology:
   The project established a two-stage lifting process combining centrifugal pump drainage with screw pump production, and optimized an ESPM system tailored for the complex well conditions of horizontal shale oil wells. This enables efficient drainage and production across large platforms.

2. Five-in-One Wellbore Integrated Control Technology:
   A comprehensive “five-in-one” wellbore protection system was developed, including a reclosable wellbore switch, constant-pressure gas release valve, sand-control screen, and internal coating anti-wax tubing. This system effectively addresses major challenges such as wax deposition, sand production, gas lock, and blowout prevention in horizontal shale oil wells, achieving rapid, safe well commissioning and stable, high-efficiency production.

3. Dynamic Balanced Production with Intelligent Data Acquisition:
   An automatic data acquisition system for downhole pressure, electrical parameters, and other key indicators enables real-time condition analysis and diagnostics for balanced pressure control. Coupled with photovoltaic power generation, the system achieves efficient and green oil recovery across large platforms.

Main Uses and Technical Principles:

This technology meets the operational demands of long horizontal shale oil wells on large platforms by applying rodless lifting systems, innovative drainage processes, integrated supporting technologies, and dynamic balanced oil production methods. It enables intelligent, large-scale, and cost-effective rodless production.

The technology addresses four major challenges faced by conventional mechanical lifting in large-platform horizontal wells:

1. Complex Well Trajectory and Severe Rod Wear:
   Rodless lifting eliminates mechanical rod–tubing friction, solving the problem of severe wear caused by large well deviations.

2. Fluctuating Post-Fracturing Liquid Volume:
   After fracturing, shale oil wells exhibit high variability in liquid output. Conventional lifting requires frequent equipment changes, increasing cost and operational risk. The rodless pump system provides a wide displacement range (5–80 m³/d), meeting full lifecycle production needs and avoiding repeated investment.

3. Harsh Wellbore Conditions:
   Coexisting wax, gas, and sand severely limit the long-term stable operation of traditional lifting equipment. The developed integrated control tools ensure stable performance under complex conditions.

4. Intelligent Pressure Balance and Efficiency Improvement:
   Through automatic parameter acquisition and dynamic balancing, the system achieves uniform pressure relief and enhanced recovery efficiency.

The project ultimately formed an intelligent rodless production system tailored for large-platform horizontal shale oil wells, accelerating efficient shale oil development in Changqing Oilfield.

Technical Applications:

From 2022 to 2025, Changqing Oilfield Shale Oil Development Branch deployed rodless production systems in 138 wells. After three years of continuous optimization, a mature supporting technology suite for large-platform horizontal shale oil wells was established.
This technology has been widely applied in large-scale development platforms such as Hua H40, Hua H50, Hua H60, Hua H100, and He H60, showcasing its high-efficiency, intelligent, safe, and green advantages.

It established new methods for efficient lifting in complex horizontal wells, contributing to higher system efficiency, reduced operating frequency, intelligent upgrades, and low-carbon transformation of mechanical recovery systems.

Notably, it achieved breakthroughs including:

• Hua H90-3: Asia’s longest rodless production well.

• Hua H100: Asia’s largest onshore rodless oil recovery demonstration platform.

As unconventional shale oil and gas development advances, the “large-platform, multi-layer, three-dimensional” long horizontal well development model will be key for maximizing reservoir utilization. The emphasis on efficiency, land conservation, and environmental sustainability will further accelerate the application and promotion of this rodless lifting technology, ensuring broad development prospects and strategic significance for China’s unconventional energy sector.