AMR.524-527.1565
Simulation and Design for Bidirectional Hydraulic Control Check Valve
of a Logging Instrument
Minqiang Dai 1, 2 a , Shengdun Zhao 1,b
and Wei Cai 2,c
1School of Mechanical Engineering, Xi'an Jiao tong University, Xi'an, 710049, China
2
Xi’an Research Inst. Of Hi-Tech, Hongqing Town, X’an, P. R. China a dmq0739@https://www.360docs.net/doc/a14880730.html,, b bsdzhao@https://www.360docs.net/doc/a14880730.html,, c 53935060@https://www.360docs.net/doc/a14880730.html,
Keywords: Logging Instrument, Bidirectional hydraulic control check valve, Formation fluid, Cartridge, Simulation
Abstract. Logging instrument are work in severe environment such as 140 MPa formation pressure, H 2S corrosive content, 50 hours continuous working time, 175 ℃ ambient temperature without heat dissipation etc. The paper designed the bidirectional hydraulic control check valve which is a key control element of MDT logging instrument. And a simulation model was established based on AMESim to analyze the structure and function of the design.
Introduction
With the development of modern economy and society, the energy requirement is increasing. However, the global oil and gas exploration has become more and more difficult. Logging reservoir evaluation encountered with many difficult problems such as carbonate, volcanic rock, metamorphic rock , low-resistivity sandstone etc. complex lithology oil and gas reservoirs. The traditional logging technologies have not be able to find such complex lithology oil and gas reservoirs efficiently. To promote the further development of oil and gas exploration industry, a new technology Modular Formation Dynamics Tester (MDT) Logging was brought into the exploration of complex reservoirs, which is an advanced and mature technology that can directly and effectively obtain formation information and find the oil and gas reservoirs [1].
The bidirectional hydraulic control check valve designed by this paper is a key control element in MDT pumping module. As logging instrument, MDT has severe working environment, for example, the formation pressure is up to 140 MPa, the corrosive content such as H 2S, the continuous working time is up to 50 hours, the poor heat dissipation, ambient temperature is up to 175 ℃, the small working space underground, and the radial dimension is less than 120mm. Therefore, it’s all parts and components should have small size as possible, compact structure, and higher performance and reliability [2]. The paper designed the structure of the bidirectional hydraulic control check valve through simulation analysis.
Design of Bidirectional Hydraulic Control Check Valve
Working Principle. The bidirectional hydraulic control valve is the key control element in MDT pumping module. In the process of oil-gas exploration logging, formation tester is often started out flush with the mud filtrate, and it does not represent the type and nature of reservoir fluid. In the case of deep invasion, the pumping module management emissions, long time out, drain, to get a representative of the fluid [3]. Working principle of Pumping module in MDT shown in Fig. 1.
Structure Design. Since pumping Modules for a long time pumping formation fluid management in severe working conditions, the design of bidirectional hydraulic control check valve has a series of problems to be solved.
First, it must be designed as high reliability and maintainability because it’s fatigue failure or else failure will lead to logging failure in descending the well process, and economic loss will reach up to ten millions dollar. The structure design of the valve adopts modularization cartridge structure, which
means that valve and valve body use the common ontology, and the valve cover, valve core and other components are designed as cartridge pieces, which can be replaced after one or more times logging. Fig. 2 is shown as the structure principle of the bidirectional hydraulic control check valve.
Fig. 1 Working principle of MDT pumping module
Fig. 2 Structure of the bidirectional hydraulic control check valve Second, the valve port sealing uses hydraulic pressure assisting sealing to increase the valve mouth sealing pressure to prevent leakage because it’s main runner uses formation fluid whose filtration precision is only 0.4 mm, and composition is solid, gas, liquid three-phase mixture.
Third, it’s materials of valve components should not only involve high strength, but also have strong corrosion resistance because of it’s abominable working condition which the formation pressure can reach up to 140 MPa, and formation fluid contains strong corrosive gas, such as H2S, and formation temperature is up to 175 ℃ without radiation condition. Therefore, the valve body and the main valve core uses TC6 titanium, valve seat uses beryllium bronze QBe2.0, valve cover and the main valve core spring uses precipitation hardened stainless steel 0Cr17Ni4Cu4Nb, sealing ring use the fluorine rubber which has corrosion resistance to H2S [4].
Parameters Calculation.According to system parameters, various components size and parameters of the bidirectional hydraulic control check valve were designed and calculated which is shown in literature [4]. This paper’s design sample is shown in Fig.3.
Fig. 3 The physical map of the bidirectional hydraulic control check valve
Simulation
Simulation Model. AMESim software is engineering system modeling simulation environment which is flexible widely used in automotive, aviation spacecraft, shipbuilding industry, hydraulic and engineering machinery industry and oil industry [5].
According to the hydraulic components design library of AMESim which provides the basic structure of the module, the paper established the simulation model of the bidirectional hydraulic control check valve as shown in Fig. 4. Fig. 4 The simulation model of bidirectional hydraulic control check valve’s based on AMESim
Simulation Results. The key structure parameters of the simulation model could be obtained from the design and calculation in Fig. 2. The parameters are the main valve core spring stiffness, valve core quality, the valve core displacement corresponding over-current area, valve core and valve cover structure size, port, oil word size etc. In addition, manufacturers of components offer the simulation model of hydraulic oil parameters, hydraulic pump, electromagnetic valve and other auxiliary original characteristic curve and the parameters. According to the simulation model, we get simulation curve as Fig. 5 shows.
According to the Fig. 5, when the control flow under the high pressure oil and the flow under control entrance is suitable, the flow into zero. Down the main valve, valve core gradually open mouth, the formation fluid flow valve core. And the valve mouth closed, the flow is zero. Then the high pressure oil flow control, the control piston movement way is contrary, on the main valve core opened up, system flow through the valve, the flow under main valve is closed, and the flow is zero.
Fig. 5 The simulation curve of bidirectional hydraulic control check valve’s work process The simulation results show that the valve working condition and the design requirements working principle is consistent, the design of valve parameter are rational, and meets the system requirements.
Conclusions
The bidirectional hydraulic control check valve is a key control element in MDT pumping module which works on severe condition. It should have small size as possible, compact structure, and higher performance and reliability. Considering the severe working environment, we designed the structure of a bidirectional hydraulic control check valve, then established it’s simulation model based on AMESim. From this research, the following findings can be concluded:
(1) Modularization cartridge structure is beneficial to the servicing and installing.
(2) The bidirectional hydraulic control method uses hydraulic pressure assisting sealing to increase the valve mouth sealing pressure to prevent leakage is effective.
(3) The simulation results show that the design of bidirectional hydraulic control check valve meets the system requirements.
However, we have to do experimental tests in future.
References
[1] Tim Ireland, Jeffrey Joseph. The MDT Tool: A Wireline Testing Breakthrough. Oilfield Review,
England, Apr. 1992: 58-65.
[2] Dawei Lu, Congqian Ning, in: China Petroleum Exploration, Mar. 2003: 58-66.(In Chinese)
[3] Minqiang Dai, Shengdun Zhao, Xiaomei Yuan, in: Advanced Materials Research Vols. 341-342
(2011) pp 848-853, edtied by Liu Guiping Publications/Trans Tech Publications.
[4] Xiaomei Yuan, Minqiang Dai. Dual channel two-way check valve design and calculation
instructions. CNPC Well Logging Technology Center，2010.(In Chinese)
[5] Yong Guo, DeSheng Zhang, Qian Ji. Study on Hydraulic Circuit Simulation Based on AMESim
for Boom of Excavator. Hydrodynamics & Hydrostatics, Dec. 2007: 96-98.(In Chinese)
Natural Resources and Sustainable Development II
10.4028/https://www.360docs.net/doc/a14880730.html,/AMR.524-527
Simulation and Design for Bidirectional Hydraulic Control Check Valve of a Logging Instrument
10.4028/https://www.360docs.net/doc/a14880730.html,/AMR.524-527.1565