Design Of Test System For Subsurface Safety Valve

With the gradual transfer of oil and gas exploration from land to the sea, oil and gas projects are facing a more severe challenge under the condition characterized by high temperature, high pressure and severe corrosion. Subsurface safety valve is one of the key tools in well completion system. The related research such as valve sealing and self balancing also suffered greater technical challenges. So, more efficient, accurate and rigorous test to the performance of subsurface safety valve is increasingly important.According to the main test content of subsurface safety valve, a test system which takes computer as the control center is designed, including structural design and control system design. The main works are as follows:1. The structure of test system is designed, including hydraulic control unit, liquid test unit and gas test unit. The last two units share a set of high pressure pipeline to make the system simple.2. In control system, stable and precise signal conditioning circuit process measurement signal for data acquisition card. LabVIEW program based on virtual instrument(VI) is developed, which has the characteristics that high speed data acquisition, real-time display and automatic storage.3. By applying wavelet analysis method to safety valve test, feature extraction of test signal is studied. Process of liquid control pressure is analyzed. Following 8 nodes are extracted. The selection of optimal wavelet basis is studied to rapidly recognize the two “key feature points” that the full open point and the full closed point in mass liquid control pressure data.4. Field test verifies the function of system and the practical results of signal processing by analyzing the test curves of the system.In the end, the whole work of this paper is summarized; further researching direction is also prospected.