The HNDCS technology for branch Wells of thermal recovery heavy oil reservoirs in Jianghan Oilfield has achieved a breakthrough
Recently, good news came from the site. The second round of the first branch well of Bamianhe in Jianghan Oilfield, Well Face 120-1-Ping 20, adopted the dual-gas synergy of nitrogen and carbon dioxide, and iteratively formed the HNDCS technology. In the initial stage, it achieved a daily oil production of 16.6 tons, which is more than three times the average single-well production in the block. This marks that the upstream integrated cooperation has taken root and flourished in the Qinghe oil area. Take firm steps towards the goal of "fewer Wells and higher yields".
Well 120-1-Ping 20 is located in the Caoxia 52 well area. Due to the thin reservoir thickness, high crude oil viscosity, and the presence of a water layer on top, it has not been effectively utilized. Since 2024, technicians have, through meticulous structural characterization, formulation of oil-water layer interpretation maps, and research on the distribution description of reservoir advantage zones and interlayers, learned from the experience and practices of the two blocks of Danjiasi in the Binan Oil Production Plant of Shengli Oilfield, and comprehensively deployed six horizontal Wells and branch Wells.
In 2024, the 120-1-ping 20 well will be given priority for implementation to evaluate the thermal recovery capacity under the new well type conditions. The well started its first round of steam injection on September 24, 2024, injecting 30 tons of viscosity reducer, 120 tons of carbon dioxide and 3,600 tons of steam. It was put into operation on October 18, 2024, and the pump was put into operation on November 12, with a total oil production of 1,048 tons. In response to the issues of temperature drop and rapid decline in production after the first round of steam injection, researchers conducted a pilot test of nitrogen injection into the annular space before steam injection to reduce wellbore heat loss. They innovatively developed the HNDCS technology, which fully utilizes the heat insulation and heat preservation effect of nitrogen. During the injection process, nitrogen and steam push the viscosity reducer into the oil layer, jointly reducing the viscosity of crude oil. Nitrogen is distributed in the middle and upper parts of the oil layer. Reduce the heat loss caused by steam overshoot. On March 5, 2025, the second round of injection at Well 120-1-Ping 20 was initiated, with 60,000 cubic meters of nitrogen, 30 tons of viscosity reducer, 300 tons of carbon dioxide, and 2,600 tons of steam injected. The injection was put into production on March 31. In the initial stage, the 8mm nozzle injection produced 39 tons of liquid and 18.4 tons of oil per day, with a water content of 52.7%, an oil pressure of 3.2MPa, and a set pressure of 7.6MPa. Achieve a remarkable oil-increasing effect.
Next, researchers will conduct a detailed description of the oil reservoir in the Caoxia 52 well area, continuously improve the efficient potential tapping plan for ordinary heavy oil reservoirs, and do a good job in the geological design of the well location and geological guidance technical support to assist in the efficient development of Jianghan Oilfield.