Research On Intelligent Well Tubing Damage Monitoring And Leak Location Technology

Tubing as the important channel of oil and gas transportation plays an important role in the industry of oil recovery. Once the tubing damaged and leaked, oil and gas production may be influenced, besides severe problems such as tubing broke off and oil well failed may be caused. Because of the limited down hole signal acquisition and data transmission control technology, tubing detection of horizontal well is given priority to off-line inspection. Tubing damage inspection usually happens on the period of tubing being run into oil-well bottom or being pulled from the well or well being repaired. Real time on-line monitoring of tubing damage could not achieved at the manufacturing stage, so operation security of tubing could not be ensured. In the recent years, problem of down hole signal acquisition and data transmission control have solved by the emergence of intelligent well technology, which makes the on-line monitoring of tubing possible. So research on intelligent well tubing damage monitoring and leaking location conducted in this article.Research on technology of intelligent well, pipeline damage and leakage detecting were conducted in this paper. Tubing damage monitoring method based on FSM, tubing leakage location method based on pressure sensor array were chosen as the best method for intelligent well tubing damage monitoring and leaking location according to actual conditions.Intelligent well tubing damage monitoring theory was proposed. Modified FSM tubing damage monitoring model was given. Influence of temperature variation to tubing damage monitoring was analyzed. Electrode arrangement of circumferential and axial direction was proposed. Potential simulation of localized corrosion and uniform corrosion was analyzed. Overall design of intelligent well tubing damage monitoring system was given.Transient pressure gradient leak positioning method was proposed for the increased or decreased tubing pressure when tubing leaked. Detection and location method was given by leakage simulation. Key technology of transient pressure gradient method, arrangement form and number of pressure sensors, pressure signal acquisition system were discussed.At last, Pipeline circulation system was set up. Simulation experiment of Intelligent well tubing leakage was conducted, which proves the feasibility and effectiveness of transient pressure gradient method. Influence of arrangement form and number of pressure sensors, leakage size and some other factors was researched by experiment.As the first tempest, this research contributes to ensure operation security, reduce accident of tubing damage. It makes great sense to down hole tubing online monitoring research in the future.