Some problems of PDC bit mixed oil diamond bit

2020-10-20 19:38:39

Causes of oil mixing and rock cuttings broken by PDC bit

　　 In order to ensure the stability of the borehole wall and the unblocked borehole, to prevent the occurrence of stuck drill accidents; drilling engineering adopts the process of mixing oil with drilling fluid. The application of this technology greatly improves the performance of the drilling fluid, stably lubricates the well wall, quickly shortens the well construction period, greatly reduces the occurrence of downhole accidents, and achieves direct economic benefits. However, the use of geological drill pipes in this process has a great impact on the geological work and increased the difficulty of the work; the drilling fluid is mixed with crude oil, which contaminates the cuttings in the well, and it is difficult to distinguish under fluorescent lights. Which one is oil sands, which one is not; under such circumstances, it is easy to cause misunderstanding by geologists, so that mistakes in misdepicting the oil layer occur, reducing the quality of logging and causing losses.

　　How to improve the logging quality of triangular drill pipe under the condition of oil mixing and PDC bit

In geological logging, when drilling into salt layers, mud-gypsum layers, and gypsum layers, the viscosity of the drilling fluid will increase, and it is difficult to clean the cuttings where mud cake and cuttings are bonded together. The engineering uses screw and PDC drilling, so the collected cuttings are often thin and mushy, and it is more difficult to clean it; and because the oil sand is relatively loose, even if the cuttings are thoroughly cleaned, the loose oil sand will be carved. The grooved drill pipe was cleaned into powder, but no sand (oil sand) could be found.

Therefore, cuttings collectors are required to be proficient in cuttings cleaning techniques, and technicians are required to master the accuracy of cuttings logging late time; understand the structure and distribution of the formation in this block, and compare and analyze with adjacent well data in time. Make a judgment on the lithology and physical properties of the stratum drilled by this well.

　　 Impact rotary diamond drill bits are mainly impregnated diamond core drill bits, which are commonly used in hard "slip" formations and are commonly used with high frequency and low impact energy hydraulic impactors. Structural features:

　　(1) Artificial impregnated diamond drill or polycrystalline drill is preferred;

　　(2) Use high-strength diamonds or diamonds that have been rounded and metal-plated;

　　(3) Since the impact toughness of diamond single crystal is inversely proportional to the particle size, the particle size should not be too large. You can choose 70~80PDC drill bit diamond with a diamond concentration of about 75%;

　　(4) The carcass must have sufficient strength and hardness to avoid impact cracking. Generally, a hard-hard carcass is selected. The shape of the lip surface should be flat, circular and concentric-pointed teeth;

　　(5) Due to the large amount of flushing fluid, the water area of the drill bit should be increased. In addition to the main nozzle, a secondary nozzle shall be added to lengthen and deepen the water tank on the inner wall of the drill bit steel body, and appropriately increase the outer diameter of the carcass.

　　Linqing Huanye Machinery Co., Ltd. is a manufacturer of geological drill pipes and PDC drill bits. It is mainly engaged in the development and sales of various grooved drill pipes, triangular drill pipes and diamond composite drill bits. The source factory produces and sells itself, with good quality and low price!