The Research Of Technology On Whipstock Window Milling With Coiled Tubing

Coiled tubing drilling technology, a very popular new drilling technology, rise in the international oil industry in the late 20th century. This new drilling technology uses a continuous length of tubing to replace the conventional drill pipe, increase the use of a screw downhole drilling assembly to replace conventional drilling in the role of turnable.Coiled tubing itself has no joints, no variable diameter, bending, continuous tripping, dynamic packing, high intensity, high pressure resistance, small size and easy transportation characteristics. This technique does not require stopping the pump and make a connection in the drilling process, and can achieve the continuous circulation of the drilling fluid, improve the speed of tripping and job security, reduce the drilling time and drilling cycle. The old oil fields, by using the CTD technical to reentrant deepen or sidetrack, not only can save the cost of drilling, but also can be found and develop the new reserves, contribute to the stable output of old oil fields, enhance oil recovery and increase oilfield efficiency. At present, many oilfields in the world has entered into the production tail, most of the oilfields in our country has entered into high water-cut stage, and the producibility is decling. A considerable part of oil and gas reservoirs with low permeability and special oil and gas reservoirs has not been put into development, or not fully play it’s role. So, It is pivotal to deeply explorate and secondary develop for these oilfiled. Directional wells play an important role in many field development strategies. Sidetracking out of an existing wellbore is one specific application of directional drilling. It is undoubtedly that the coiled tubing sidetracking technology is one of the most suitable technology to solve the above problems. Combined with the significant professional project of the National Science and Technology (task 6 of project 36) "The coiled tubing equipment and the application of technology" research the process for coiled tubing sidetracking. The purpose of the study is very important, the research results can be used to guide the field of coiled tubing drilling test, and initially formed the process of research reports for the old well sidetracking with CTD, and make some contribution to the development and improvement of CTD technology. This paper mainly study from the following aspects:(1) Study abroad coiled tubing surface equipment and downhole window milling tools, to deepen understanding of coiled tubing equipment, to fully understand the advantages and disadvantages of coiled tubing equipment, when during coiled tubing operations can match the right downhole tools.(2) Combine the actual situation of test well and the collected coiled tubing one-trip window milling tools, recommended two sets of window milling tool assemblies, and the BHA strength were been checked.(3) Combine the Jiazhi model and metal technology in the milling plane models, derivating the formulas of the milling parameters in theory. Using the basic data in test well to calculate the circulating pressure loss during window milling.(4) Spot coiled tubing drilling bridge plug specification as a guide, combined with the construction process of conventional drill sidetrack window milling and coiled tubing special construction program, to work out the coiled tubing window milling construction process.