Abstract: In Changqing Oilfield, tight oil production has a long history and a large scale, and it remains a key target for production capacity construction at present, accounting for 36.6% of the new production capacity. In response to the geological characteristics of tight oil reservoirs, and targeting at the goal of an optimal adaptation between well pattern and fracture network, the geology and engineering integrated research approach is applied to conduct fracturing optimization design using methods such as numerical simulation, big data analysis, and field test. As a result, the coiled tubing precise multi-stage fracturing technology for short horizontal wells has been developed, as well as key integrated technology of “optimization of fracturing timing, differential fracture design, precise fracture control, enhanced imbibition oil displacement, multi-stage fracture temporary plugging, and directional perforation”. This technical model has been applied in over 200 tight oil wells in Changqing Oilfield, significantly improving the degree of fracture control and oil production in horizontal wells. Microseismic monitoring results show that the degree of fracture control has increased from 60% to over 85%, the initial oil production of a 100-meter horizontal section has increased from 2.0 t/d to 3.4 t/d, and the single well production remains steady, with an oil production rate of 3.2 t/d in the year of reaching production capacity, showing satisfactory results as a whole. The key fracturing technology effectively supports high-efficiency development of tight oil in Ordos Basin and points out direction for further technical breakthroughs. The new insights provide references for large-scale and beneficial development of similar oilfields in China.

Key words: Ordos Basin, tight oil, fracturing technology, geology and engineering integration, waterflood development