STEPPED HORIZONTAL DRILLING TECHNOLOGY

Stepped horizontal drilling technology, a method that realizes the hitting of 2 horizontal targets in a well, indicates a new stage in horizontal drilling. It involves the process of angle dropping, holding and building up before drilling into the second target interval. The application of this technology makes the horizontal drilling available for developing the conventional reservoir, continuous thin reservoir and such complicated reservoirs as fault-block reservoir. The paper mainly discusses the operation difficulties, drilling plan optimization and trajectory control, and gives the operation data of 3 wells for examples, e.g., well TZ406, YX2P1 and LN61-H1. In which, well TZ406 is detailed on its drilling plan, trajectory control technology, and drilling practice, etc. This technology greatly improves the production of horizontal well, and will be one of the important methods for oilfield developing in the future.