Workover operation refers to an operation of care and maintenance measures for oil drilling and subsequent well maintenance to ensure successful well use. With continuous development of oil fields, oil-well failures may occur during natural flowing, oil pumping or water injection process due to various factors and at this time, normal production can only be restored through workovers to replace downhole equipment and adjust parameters of the well. Workover process is developed with the extension of oilfield development time and the development of oil production process. Workover process was formerly a part of the oil production process and as for the need of process where the well structure may be changed, such as drilling, grinding, cementing and other processes plus some of the drilling process and parameters, so workover has developed into an independent process on the basis of drilling process and oil production. As for the project difficulty and high technical requirements demands large workover equipment with overhaul drill pipes, turntables and other special equipment, therefore, only professional process company of certain strength can be engaged in the workover.
Dragon provides specialized workover services in wells of over 7000m at different oil and gas formations. These services includes pull-out casing and replacement, stuck point measurement, cutting removal, plugging removal, pipe making-up, , side tracking and milling and fishing.
Well failure, such as downhole sand blocking, wax and salt deposit within the shaft, reservoir choke, permeability decreases, collusion of gas-water layer and etc.;
Well string structural damage, such as tubing fracture, tubing joints tripping, casing leakage due to collapse and fracture;
Oil production equipment failure such as oil pumps, electric submersible pumps and progressive cavity pumps failure.
Scope of business
Including POOH, repair, replacement, and then RIH of failed or damaged tubing, pumping rod, oil pump and other BHAs and tools and pumping, bailing, wax scraping and the like;
Cycle operation within the well
Including sand washing, hot wash, recycle slurry, cement squeezing and etc.;
Including drilling out sand plug, drilling out the cement plug, reaming, re-drilling, side tracking, casing fixup and etc.
Including workover rig , electric control, rotating equipment, pump and cement application, surface facilities, wellhead blowout
preventor, control, barracks and auxiliary equipment system. The accessory equipment and parameters are both perfect . It has been equiped with 2 3/8” drill pipe 2000m, 2 7/8” drill pipe 4000m, 3 1/2”drill pipe 3000m, drill collar, various downhole operation equipment including grinding, sets, milling, fishing, etc. And the well repair equipment and other facilities are also fully equipped with.
• Equiped with 2 pairs of diesel engine and ALLISON transmission case ;
• Full-blown paralleled twin-engine transfer case and transmission structure ;
• Thickening rectangle derrick 36/38m ;
• 14x8 intensive chassis , optional double-tire structure, strong ability of off-road driving;
• Optional 5.5/6m folding drill floor and doghouse ;
• Optional top-drive system.
• Utilizing 34m (11.55ft) binodal hydraulic raising and telescoping derrick
• Utilizing 12×8 self-propelled chassis ;
• Auxiliary brake of winch is water brake system, can choose gas-controlled water cooled plate brake or air pressure pincer brake.
• Turntable rotating system uses four-output transfer case, transmitting through transmission shaft and intermediate shaft;
• Utilizing five-to-five anti-reverse rotary actuator;
• Optional sucker rod hanger.
Since 2010, the overhaul workover team from Dragon Oiltech implement over 100 various ultra-deep wells, including TH12143X drilling and bottom hole deepening, sand washover of open hole section at 6900 meter in TH12513 well, drilling tool fishing in TK668 well, packer deblocking implementation in TH121107open hole horizon and other wells, reached the design requirements in high quality and in high performance with a construction success rate of 100%, was awarded the second prize 2013 for high quality project in No.2 oil production plant of Northwest Oilfield Branch, the third prize 2014 for well control contest drills of Northwest Oilfield Branch, and the first prize 2014 for high quality project in No. 2 oil production plant of Northwest Oilfield Branch.