Study On Hydraulic Purification Of Extended Reach Well

Extended reach well drilling technology began in the1920s, is refers to the horizontal displacement and vertical displacement of the oil and gas Wells is no more than2. Main characteristic is the long horizontal displacement, deviation Angle is big. With the rapid development of science and technology level, Extended reach well drilling technology Includes a variety of high-tech, integrated a number of disciplines and supporting technology. Extended reach well drilling technology has become the most effective way to Small offshore oilfield and marginal oilfield exploration and development, is the advanced technology of well drilling. The current horizontal displacement of foreign Extended reach well is already over Ten thousand meters, the longest domestic horizontal displacement is xijiang24-3-A14Extended reach well, the horizontal displacement Reached8063meters. In addition, the south China sea liuhua Extended reach well, the ratio of horizontal distance and vertical distance is6.13. Compared with the conventional drilling, hole cleaning is particularly important in the Extended reach well drilling technology, it is the key to economic,rapid and safe drilling of Extended reach well.Wellbore purification is not good, will produce many harmful to Extended reach well drilling, such as:increase in friction and torque affect normal drilling, such as sticking borehole problems, under the influence of casing and well cementing operation, etc.Because of cuttings migration problem itself has a lot of study difficulty, add in Extended reach well drilling process, many factors influencing the cuttings migration, in different hole deviation of cuttings migration and each is different, so this problem becomes more complicated. Although for a long time, the researchers conducted a large number of experimental studies and theoretical research, the qualitative evaluation and the application in the field provide some guidance. However, existing models are difficult to predict the thickness of the cuttings bed or area:some model calculation is convenient, but the scope is narrow, can’t reveals cuttings migration law essentially; Some model of inclined section and horizontal section is easy to produce large error, and though the model is closer to the actual cuttings migration process, but calculation is complex, are not suitable for engineering application. So, a more comprehensive and systematic to analyze the main factors influencing the wellbore cleaning experiment has very important significance, to the study of the hole cleaning still needs a lot.This paper research a large number of domestic and foreign literature at first, to grasp the basic theory of cuttings migration concentration, summarizes the mechanism and influencing factors of cuttings migration in various sections of the well, summary the research achievements of Extended reach Wells hole cleaning by comprehensive. Secondly, use the high angle deviated hole carrying effect Simulation evaluation device to experiment, focusing on the cuttings migration form along the long horizontal section, and put forward some new cuttings migration form opinions and views and Suggestions about carrying rock experiment, make hole cleaning research in the field of practice can be more in-depth, more comprehensive analysis of the influence factors of hole cleaning, systematically grasp the cuttings migration rule, and to verify this model of hole cleaning, to provide the reference for the further research in the future extended reach well hole cleaning problems. Finally, the common hole cleaning model was classified and summarized, based on Visual Basic6.0development tools, Microsoft Excel2003as database management system, develop the hole cleaning applications, Basically meet the hole cleaning and construction requirements of extended reach well drilling, can assist the technicians to accurately grasp the hole cleaning conditions, thus achieve the purpose of practical application.