Daqing Oil Production Plant No. 2: Combination Technology Development Oilfield "Potential Stock"

As of December 7, the second oil production plant of Daqing Oilfield has explored and implemented technical means combining the optimization of the oil flooding system and the overall fracturing auxiliary development through scientific and technological research, deeply tapped the remaining oil potential in the transition zone, increased the recovery rate by 13.
02 percentage points, and increased the cumulative oil by 146,000 tons
.

"As the 'potential stock' of our oilfield development, it is imperative to carry out technical research to tap the remaining oil potential of the region
.
As early as the 'Eleventh Five-Year Plan' period, we tried to carry out poly-excavation in the transition zone, but the effect was not satisfactory, only 12.
9%
of the total geological reserves in the area were tapped.
In recent years, the development technology of ternary composite flooding has become increasingly mature, and good development results
have been achieved in the pure oil area.
Drawing on this experience, we conduct field trials in the preferred blocks and potential layers in the transition zone area to explore the feasibility
of applying ternary composite flooding technology to enhance oil recovery in the transition zone.
Ma Yuan, director of the third recovery office of the Institute of Geology of the Second Oil Production Plant of Daqing Oilfield, said
.

Compared with the pure oil area, the transition zone area has the characteristics of
low sand drilling rate, high proportion of thin layer, low permeability level and high argillaceous content.
This leads to a large adsorption loss of ternary composite chemical displacement agents in the development process, and it is difficult to achieve a better displacement effect
.

In the face of difficulties, the scientific and technological personnel of the plant "took an unusual road", constantly broke through the technical bottleneck, comprehensively optimized the ternary composite flooding system in the experimental area of the transition zone, and after repeated verification of indoor tests and more than 100 corrections of key parameters, finally determined the optimal surfactant concentration value and the dosage of the main section plug, and increased the recovery rate by 1.
88 percentage points after application, ensuring that the economic benefits reached the best
.

At the same time, they also applied integral fracturing technology to assist development, changed the design of fracturing scheme from single well to well group and block overall optimization, changed the fracturing timing from fracturing efficiency improvement in the effective period to pre-injection agent preservation and replacement, and the effective thickness ratio of liquid absorption in the test area after implementation reached 83.
1%, which increased by 26.
2 percentage points compared with the blank water flooding stage, and realized the effective displacement
of chemical agents.

On this basis, the plant aims to promote the balanced effect of the test area, and implements accurate dynamic tracking and adjustment
of the whole process in the development process.
In the blank water flooding stage, they grasped the key of balanced injection pressure, through the comprehensive implementation of injection well washing, comprehensive admission and verification of basic information, amplification of allowable injection pressure difference, improvement of injection production ratio, to ensure the injection effect, the stage completed well washing, measures, adjustment of the workload ratio reached 108%, compared with the plan to achieve the injection condition
1 month earlier 。 In the injection stage, they grasped the core of the whole process of classified well group adjustment, established a matching plate between the concentration and permeability of the classified well group, personalized designed the injection parameters of the classified well group, and strengthened the tracking adjustment in the later stage to ensure that the injection pressure continued to be stable, and the overall injection speed was 10.
4 percentage points higher than the plan, compared with other blocks in the same stage, and achieved full effect
of the well group 2 months ahead of schedule.