Research On Anti-Drilling Characteristics And Increasing Drilling Speed For Marine Formation In The Northeast Area Of Sichuan

The marine deposit formation of Northeast Sichuan is the main battlefield of oil reserve resources for Sinopec. However, the reservoir formations are buried deeply and have high hardness. All these disadvantages bring lots of difficulties for the highly-efficient drilling. In order to speed up the progress of exploration and development, the method of anti-drilling parameters prediction in the carbonate formation, drilling methods selection and efficient rock fragmentation tools optimization design were deeply studied combining the methods of laboratory test, statistical analysis and theoretical research. (1) The anti-drilling parameters such as drillability, compressive strength, internal friction angle, hardness and plasticity coefficient were measured through laboratory experiments. Based on this, the relationship between these anti-drilling parameters and logging information were researched and this paper established the methods that using the logging data to predict the formation anti-drilling parameters. (2) Collecting the geological information and logging information, we summarized the lithologic features and anti-drilling characteristics of the carbonate formation in the northeast of Sichuan. (3) Through comparing and analyzing the rock breaking mechanisms and using features of different drilling methods, the article summarized the appliable characteristics of different drilling methods. Based on the summary analysis of cost component of drilling methods, we established the cost model to evaluate the using effects of different drilling methods. (4) Gathering the well completion data, the paper analyzed the drilling methods that have good use effect. The petroleum drilling formation was classified reasonably using the fuzzy clustering analysis method with the classification basis as formation anti-drilling characteristics. The principle and the way to optimize the drilling methods according to the stratum anti-drilling characteristics were determined. According to anti-drilling characteristics of marine stratum in the northeast area of Sichuan, the most efficient drilling method was selected. (5) The PDC bit using condition in the marine formation were analyzed through collecting the well completion information in the northeast area of Sichuan. Aiming at the problems, through the microbit experiment we selected the best cutter size and back rake angle for the PDC bit in the marine formation. The article developed a new individualized PDC bit including the profile design, teeth arrangement design, force balance design and hydraulic design.