News

The no-guyline workover rig refers to the design process of the workover rig to remove the outer guyline, only keep the inner guyline; The conventional workover rig must be in a stable state during operation, which is maintained by outer guyline. After removing the outer guyline, the stability of workover rig operation must be guaranteed by itself. The no-guyline workover rig is a simple design change from the point of view of removing the outer guyline, but since the workover rig is operating to pull more than 30 tons of weight, its stability is an absolutely important technical requirement. The first no-guyline workover rig in China is developed by our company, which fills a gap in domestic petroleum machinery manufacturing. Developed background: At present, the conventional workover rigs are most used at domestic and abroad. However, with the expansion of oil and gas exploration to mountainous areas, deserts, beaches and extremely cold regions, conventional workover rigs are becoming more and more unsuitable. In flat areas of the mountainous can be fixed outside the rope, but the site is limited by the size of the area, and increase the cost.In deserts and beaches, where the ground formation is soft and it is impossible to fix the outer guyline, so a new type of workover rig is in need, which it can maintain the stability of the equipment without the outer guyline, and to maintain the safety operation by the stability of itself. In June 2006, our company took the lead in developing the workover rig without guyline to complete the workover operation of the above site with its own stability, and we decided to start developing from the workover rig in small load, laying a foundation for the development of the workover rig in large load without guyline. In December 2007, the prototype of the first 40-ton no-guyline workover rig was completed. In March 2008,the test of prototype was completed. In Oct.2008,we got the invention patent. The key technology: 1.Compared with the conventional workover rig, due to the stability of the equipment itself to maintain the safety and reliability of the operation, so the system needs to be redesigned and do the matched calculation with the chassis, the accuracy of calculation is the key to ensure the design of the no-guyline workover rig. 2.That whether the stability of the support mechanism can replace the pull force of the four outer guylines and the structural design of the support mechanism are the key technologies of the no-guyline workover rig. After the calculation of the supporting mechanism design, the automatic tie bar is adopted to connect the mast body and the rear support, and the large-span hydraulic telescopic jack structure at the tail of the chassis is adopted to increase the distance between fulcrum points, so as to improve the stability of the whole machine. 3.The design of the mast is analyzed by stress finite element method, and the side of the mast is designed as a trapezoidal joint, which improves the strength of the mast. Main features: 1.Through the improvement of mast positioning, mast shape, jack arrangement, gravity forward shift, greatly improves the performance and stability of the workover rig. It is especially suitable for no-guyline workover rig design which is 60 tons and less. 2.Comparison of structure and performance between conventional workover rig and no-guyline workover rig: Item Conventional workover rig No-guyline workover rig Remark Workover depth(m) 2600-3200 2600-3200 Same Normal Load kN 300-600 300-600 Same Max.Load kN 585--900 585-900 Same Structure With outer guyline Without outer guyline Auxiliary equipment Fix the outer guyline and ground anchor, pile extractor is needed no Auxiliary operation time At least 300mins 20-40mins Improving the installation efficiency by 73% Site requirements Sufficient space must be reserved for a minimum of 30X30 Can park the no-guyline workover rig, no other more space Beaches and desert areas Unable to fix the outer guyline, the operation safety is not guaranteed Able to operate, safe and reliable As can be seen from the above comparison, in addition to having all the functions of a conventional workover rig, the most prominent difference is to cancel the design of the outer guyline. This makes the same load of no guy-line workover rig has the functions that conventional workover rig cannot complete ,that is, the workover operation can be successfully completed under geological conditions where it is impossible or difficult to fix the outer guyline. Therefore, the no-guyline workover rig is more widely applicable. And because the no-guyline workover rig removes the operation of fixing the outer guyline, does not need to be equipped with auxiliary equipments, only driving the machine to the site and aligning at the well head is enough. It simplifies the operation procedure, saves the auxiliary operation time. It has the outstanding characteristics of improving work efficiency and simple operation. This equipment can completely replace the same load of conventional workover rig, which represents the future development direction of the workover rig. Advantages: 1. The no-guyline workover rig is more effective than the conventional workover machine due to its efficient, flexible and integration. The following table can show the excellent performance of the no-guyline workover rig. Item Conventional workover rig No guy-line workover rig Structure With guy-line No guy-line Other auxiliary equipment Fix the outer guyline and ground anchor, pile extractor is needed no Rig up 53-60min 20-30 min Rig down 18-20 min 10-18 min Install time 120 min 20-40 min Site requirements Sufficient space must be reserved for a minimum of 30X30 Can park the no-guyline workover rig, no other more space Load rating 180t and below 60t and below(or 40t) Back support Y-shape With oil jack Support system Only leveling jacks Two transverse telescopic oil jacks are installed at the bottom and rear of the no guy-line workover 2.Time saving, efficiency improvement, and cost reduction Item No guy-line Workover rig Conventional workover rig Time saving Rig up 20min (open oil jack 8min) 53min (fix anchor 20min,install guy-line 20min) 33min(62%) Rig down 10min (close oil jack 7min) 18min (recycle guy-line 16min) 8min(44.4%) Total 30min 71min 41min(66%) It is clear to know from the above table that the no-guyline workover rig does not need to adjust the turnbuckle. Compared with the conventional workover rig , the up and down rig are faster than the conventional , saving 41 minutes per well. This alone increases efficiency by 66%.Thus greatly improve the construction progress and work efficiency, The significant cost savings can be achieved in reducing work time and improving work efficiency. Economic and social benefit analysis report: 1.Time cost The no-guyline workover rig can save cost for oilfield workover operation. The auxiliary time of using conventional workover rig includes fixing the outer guyline with special equipment and aligning at the wellhead, which both operations will take4~5 hours. The no-guyline workover rig eliminates the time of fixing the outer guyline. Only up rig and aligning at the wellhead, only take 40 minutes, which alone improves the efficiency by 73%. The cost of workover a well is about RMB30,000, and according to taking 3-day to complete one well, the ground anchor installation cost is 1,250 yuan per hour. As per the auxiliary time of 4 hours, that is, equal to save 1250×4=5000 yuan.(This calculation is based on the cost of one oilfield in China, for reference only) 2.Well site cost The no-guyline workover rig can not only save auxiliary time to improve the working efficiency, but also the important point is not limited by the site and natural environment, like the no-guyline workover rig to operate in the urban area, narrow mountains, frozen soil, beaches and others. A wellsite area is not only at least 30m ×30m, and also building a 900m2 site will take huge laying costs, including materials, labor, but also time, while the no-guyline workover rig only needs a small wellsite area, which greatly saves the building cost of the site. 3.Environmental cost The earth is the common home of human beings, no-guyline workover rig not only saves a lot of land resources, protects the ecological environment, but also less manufacture and use of large ground anchors is more environmentally friendly. With the more and more attention to the protection of the earth, the no-guyline workover rig will be more and more recognized and used in the oilfield. At present, in China, conventional workover rigs with load of 60 tons and less have been replaced by no-guyline workover rigs. Now, in the annual procurement, the proportion of the no-guyline workover rig is as high as 93%, which fully reflects the market`s recognition and demand for no-guyline workover rigs.