| Depositional environment of Hailar basin is complex, some strata with unequal thickness and unconformity layers. Especially, Formation below the Nantun 2 bed is based on siltstone and sandstone, lithology hard, strong abrasive, so the drilling speed is slow and trajectory control is difficult. Drilling technology of bottomhole high pressure spray is applicable to the hard and deep formation and the formation difficult to control wellbore trajectory and other geological conditions. It has made a breakthrough in the aspect of improving drill footage and penetration speed. Therefore, based on the technical difficulties in drilling of Hailar basin and downhole supercharger technology application condition, accelerating drilling speed technology in Hailar Basin should be carried out.Firstly, high-pressure jet breaking rock mechanism has been studied. Shear breaking rock mechanism thinks that the water jet breaking rock is mainly caused by shearing action, ignoring coupling effect, according to the Mohr-Coulomb criterion, established a rock damage evolution equation and variable constitutive equation. Water wedge swelling and breaking rock mechanism thinks that the breaking rock mechanism is similar to hydraulic fracturing process. Stress waves- the jet quasi-static pressure theory thinks that the jet breaking rock is the result of the jet coupling with rock interface interactio n, jet impact act on the surface of rock and the stress wave generating, combined with quasi-static pressure in order to breaking rock.Secondly, carrying out research on geological characteristics of Hailar basin. First of all, carry out research on litho logic characteristics of formation below the Nantun 2 bed. The lithology of layers is high hardness and strong abrasive middle containing gravel rock with thin stratum, this is the main reason for restricting the drilling speed; and then, carry out the research on the mechanical characteristics of formation below the Nantun 2 bed, the rock compressive strength is relatively the larger, and the cohesion of rock and the tensile strength is relatively small. Finally, carry out characteristics of rock grain size of formation below the Nantun 2 bed. This layer is strong abrasive, due to containing large grain size glutenite and high content sandstone; the rock is mainly cemented by shale and gray matter, and the formation of high hardness. According to breaking rock mechanism, deep formation of Hailaer Basin is suitable for drilling technology of bottomhole high pressure spray.Thirdly, though carrying out high-pressure jet breaking rock experiment under different conditions, optimize best parameters of hydraulic breaking rock. Firstly, from the results of different experimental conditions known standoff distance, decreased with increase in spray distance, the first volume of jets erosion rock increased standoff distance optimal value is about 6.0mm. Second, from t he perspective of different injection conditions known experimental results, spray angle increases, the volume of rock erosion is reduced after the first increases, the optimal spray angle were about 13.5°. Thirdly, the nozzle moving speed different from the results of experimental conditions known to increase with the moving speed of the nozzle, the volume of erosion of rock a decreasing trend. Four thly, from the jet pressure conditions under different experimental results known, according to curve the jet pressure, jet impingement jets into power and force and ? between, can get the best value of the jet pressure of 150 MPa.Finally, carrying out the application research of drilling technology of bottomhole high pressure spray in Hailar basin. Optimized downhole most suitable booster type for Hailar basin is screw rod and most suitable type of bit for Halaer basin is ultrahigh pressure double channel PDC bit. Then, according to the different experimental results, jet erosion effect angle under the angle of vertical drilling fluid flow by ultra high pressure ultrahigh pressure double channel PDC bit angle to the extending direction of the tail end of the channel and the rock surface is 13.5°; super high pressure drilling fluid flow channel diameter is 11mm; when the number of high-pressure nozzle 2 when the nozzle diameter is 1.35 mm, when the high pressure nozzle Number four nozzle diameter for 0.96 mm. finally, carry out experimental study on the downhole supercharging technology in Hailaer basin. The results show that bottom hole pressure d rilling technology can greatly improve the drilling speed, but there is a certain degree of wear and tear of the super high-pressure double channel PDC composite sheet. |
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