Experimental and Application Research on the Split-Type Long Stroke Oscillator for Water Injection Wells

When conducting fishing and testing operations in water injection wells, it is common for the fishing tool to get stuck in the well during the process of deploying and retrieving the blockage device. Currently, the on-site method for un-sticking is oscillation un-sticking, but the existing oscillation un-sticking devices have problems of low efficiency and short stroke. To improve the un-sticking efficiency and reduce operation costs, a modular long-stroke oscillator has been developed. This technology adopts a modular design, allowing for the combination of short sections as needed, with a maximum stroke of up to 800 mm. It features easy assembly and disassembly, flexible combination, and low cost. It can meet the length requirements of various-sized testing tool strings, optimize the un-sticking stroke length to the greatest extent, increase the impact force, and reduce the costs caused by well operations due to instrument sticking and inability to conduct tests. Field tests show that the average operation time for un-sticking stuck wells has been reduced from 50 min to 30 min with the modular long-stroke oscillator, increasing work efficiency by 40%. As of December 2024, it has been applied in 106 well operations, reducing operation costs and achieving economic benefits of 1.43 million yuan. It provides an efficient and economical solution for un-sticking in water injection well testing and has broad application prospects.