Dagang Oilfield: Natural Gas Huff-and-Puff Technology Delivers 7,600 Tons of Additional Oil This Year

Pain Points
After oil wells were put into production, water cut surged sharply, trapping operations in low-efficiency conditions characterized by excessive water output and limited crude oil recovery.
Solutions
Carbon dioxide huff-and-puff technology was trialed at first, yet its large-scale rollout was constrained. Natural gas huff-and-puff technology was adopted as an alternative solution afterwards.
Achievements
The comprehensive water cut of Well Gang 508-31 dropped by 67%, while stimulated wells in Banqiao Oilfield gained an incremental daily oil output of 10 tons. Large-scale deployment of this technology can boost oil recovery factor by 5%.
Faced with long-standing development challenges of high water cut, low production velocity and poor efficiency in heavy oil reservoirs with active edge and bottom water, Dagang Oilfield carried out technical research and innovation to successfully deploy natural gas huff-and-puff technology, blazing a new path for efficient heavy oil exploitation. As of May 31, this technology has generated a total incremental oil production of 7,600 tons within the year.
Heavy crude oil features high viscosity and poor fluidity. Coupled with active edge and bottom water, water cut rises rapidly after well commissioning, resulting in high produced liquid volume but low crude output. To tackle this issue, Dagang Oilfield initially adopted CO₂ huff-and-puff technology to improve development performance. Nevertheless, carbon dioxide exerts corrosive effects on wellbores and surface gathering systems, hindering its wide-scale application.
Subsequently, researchers turned to natural gas, which boasts superior compatibility with crude oil. Drawing on proven practices from Tuha Oilfield and based on the principle that natural gas can dissolve crude to reduce viscosity and optimize mobility ratio, Dagang Oilfield launched pilot tests of natural gas huff-and-puff across two well groups in Tangjiahe Oilfield and Banqiao Oilfield.
Since the implementation of natural gas huff-and-puff on Well Gang 508-31 in Tangjiahe Oilfield, the well has maintained stable incremental oil output for more than 230 consecutive days, with a cumulative incremental oil volume of 3,481 tons. Statistics show its comprehensive water cut fell from an initial 92% to 25%, with a peak daily incremental oil rate hitting 41 tons. Meanwhile, parallel trials in Banqiao Oilfield yielded promising results, with participating wells recording a daily oil gain of 10 tons.
To support effective promotion of this technology, Dagang Oilfield’s R&D team deepened theoretical studies to clarify the oil stimulation mechanisms of natural gas huff-and-puff across three phases: gas injection, well soaking and back production. Targeting core on-site hurdles such as gas channeling, technicians pioneered a segmented slug gas injection scheme paired with moderate production strategies. Precise parameter regulation significantly enhanced oil displacement efficiency. At present, Dagang Oilfield has established a complete technical system covering six links: well selection criteria, injection-production parameter optimization, as well as matched wellbore and surface processes. Large-scale adoption of this technology can lift the oil recovery factor by 5 percentage points.