Preset string completion for horizontal wells and staged fracturing integrated technology of coiled tubing with bottom packer

The conventional horizontal well staged fracturing with preset pipe string is the main technology used for the development of tight gas reservoirs in Daniudi Gasfield. During its application, however, stepped sliding sleeves are faced with stepwise reducing and the grading balls which cannot be returned totally are detained at the bottom hole. And these problems are not favorable for drainage gas recovery after fracturing, formation testing and later stimulation. The completion and fracturing technology which combines the preset pipe string completion and the coiled tubing fracturing with bottom packer together can meet the engineering technology requirements of full bore. After fracturing material selection and fracturing operation parameter optimization, this technology was tested on site in Well A, whose absolute open flow after fracturing is 6.07×10⁴m³/d. The test results were compared with the application results of its neighboring wells. It is indicated that preset string completion and staged fracturing with coiled tubing and bottom packer is much better than the cementing, completion and fracturing, and basically the same as the conventional fracturing technology with preset pipe string and open hole packer. Therefore, it can be popularized further.