New Breakthrough in Fracturing Exploration in PetroChina’s Zhundong New Area

Well Kangtan 001H is the first pre-exploration well deployed by the Tuha Oilfield in the Fukang area. It is located in the Kangtan 1 nose rise zone of the Fuzhong trough in the Fukang Depression. Since the launch of new area and new field research in 2023, researchers have systematically reviewed early exploration progress and geological understanding. In the face of complex geological conditions, they have re-understood the structural pattern, re-understood the distribution of sand bodies and high-quality reservoirs through "three re-understandings" scope, re-understand the reservoir characteristics, and propose a new understanding of overall reservoir formation, local enrichment and high production of the Upper Wuerhe Formation in the Fuzhong trough area. Through the understanding of reservoir distribution characteristics and oil-bearing properties, combined with multiple rounds of seismic attribute inversion, it has been confirmed that the sand body reserves in Phase III of the Upper Wuerhe Formation in this area are large in scale and have generally good physical properties, making it suitable for research on horizontal well production enhancement technology. The Kangtan 001H well was deployed in the high part of the nose belt.

During the drilling process, the Exploration Division quickly formed a research team on the integration of drilling speed improvement and geological steering. Focusing on the speed-up target, we leveraged the advantages of geological engineering integration and scientifically formulated a speed-up plan. Experts from Party A and Party B went to the site to promote the integration and implemented the speed-up measures at all levels. It effectively overcame drilling problems such as abnormally high pressure in the target layer, large burial depth, and poor drillability, and efficiently completed the 6,290-meter drilling task with a drilling cycle of 70.2 days and a completion cycle of 78.5 days, achieving the goals of accelerated drilling and high cementing quality 25 days ahead of schedule.

Focusing on the geological steering target of horizontal wells, the Exploration Division established an on-site joint working group, and the chief oil field expert and the company's technical expert carefully followed and provided guidance. A day and night steering duty mechanism and a supervisory duty mechanism were established on site to supervise the implementation of steering and orientation measures throughout the process, and strengthen well logging. "Dual-post" technical support has achieved a reservoir drilling rate of 91.0%.

The Exploration Division carefully organized a discussion on the test and completion plan for Well Kangtan 001H, and carried out a 14-stage 43-cluster volume fracturing oil test. Currently, a 4 mm + 4.5 mm two-stage nozzle is used for blowout, with a daily liquid production of 202.1 cubic meters, including 102 cubic meters of crude oil. , 7549 cubic meters of natural gas, and the wellhead pressure remains relatively stable above 40 MPa. It has the characteristics of early oil breakthrough and rapid increase in oil content. As the oil content ratio continues to rise, the production is expected to further increase.

The exploration breakthrough of Well Kangtan 001H confirmed that tight sandy conglomerate reservoirs with a depth of more than 5,000 meters can be efficiently exploited using horizontal wells. In the next step, the oilfield will continue to implement integrated exploration and development deployment, accelerate the expansion of reserve scale and overall upgrade and utilization, and consolidate the resource base for the oilfield's "three 1 million tons" strategic goals.