A Technological&Technical Research Of Window Cutting On The Casing With Coiled Tubing

Coiled tubing(CT) also known as flexible pipe,sinuous coil or coil pipe, is made up of a number of length in the hundreds of meters or more flexible pipes by butt welding or inclined welding welded together without joint coiled tubing.Coiled tubing is relative to the conventional tubing of threaded connection, the length can reach hundreds of meters to thousands meters. Coiled tubing drilling is a new kind of drilling technology to study abroad in the1990s, known as a revolutionary technology of oil and gas drilling method in the21st century,and contributed to a tide of new safety drilling way. Compared with the conventional drilling, coiled tubing drilling has the following advantages:①It is possible to implement underbalanced pressure drilling operation safely, and is beneficial to reservoir protection and improving drilling rate;②It is needless to stop the pump when drilling hole, which can realize continuous drilling fluid circulation, and so the benefits is reduce tripping time, shorten the drilling cycle, improved the speed of tripping and the safety of operation;③It is particularly suited to drilling a slimhole, deepening the old well and sidetracking in the hole;④It is favorable to achieve automatic control and MWD by built-in cable in the coiled tubing;⑤It is especially suitable to apply for the conditions of restricted on the ground and offshore platform, because less ground equipment and small job site can reduce the operating personnel, at the same time, to install and migrate the equipment is quick, convenient and flexible.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 dec ling. 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.It is undoubtedly that the coiled tubing sidetracking technology is one of the most suitable technology to solve the above problems.The technology does not require service unit and kill weight fluid because of without remove completion equipment,and this makes it very suitable for sidetracking on the restricted section,the commercial value is very considerable. Combined with the significant professional project of the National Science and Technology (task6of project36)"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)Research coiled tubing rig and important construction tools at home and abroad, detailed explain the working principle of important construction tools and it’s performance parameters, So that we can match the BHA in the coiled tubing drilling.(2)we can concluded that the drilling rate of the cable system BHA is higher52%than the mud pulse system by counting the using effect for the two kinds of BHA. According to the scope of application, advantages and disadvantages of these two kinds of BHA and the actual circumstances in the JiaoYe1well, this paper recommends a kind of more suitable BHA for the coiled tubing window cutting.(3) through detailed study of the construction process of conventional casing sidetracking, on the basis of the foreign advanced coiled tubing homework technology, combined with the particularity of the coiled tubing sidetracking and the experimental results on the old well deepen project, this paper will formulate a complete set of job specification on coiled tubing window cutting.(4)Combined with the crossbar bending continuous beam method and the mechanism of plane milling in the Metallurgical technology, establish casing milling model, consult the actual data in the JiaoYe1well, theoretically analyses and calculate the milling parameters, this paper will conclude the coiled tubing window cutting milling parameters.(5) According to the actual data of JiaoYe1well, we will design a construction scheme on the coiled tubing window cutting, mainly including the design of the bottom hole assembly, check ing the the drill string strength, calculating the coiled tubing window cutting milling parameters and hydraulic parameters. The scheme can be used to guide the construction on the coiled tubing window cutting in JiaoYe1well...