Southwest Petroleum University, Chengdu, Sichuan province, 610500, China.
Southwest Petroleum University, Chengdu, Sichuan province, 610500, China.
J Environ Manage. 2022 Jan 1;301:113834. doi: 10.1016/j.jenvman.2021.113834. Epub 2021 Sep 30.
Casing or tubing leaks cause unwanted water production from oil-producing wells. Many chemical and mechanic water control technologies can be used to solve this problem, including squeezing chemical shutoff fluids into the targeted zone or using plugs, cement, packers, patches to block the leakage. Although those methods are field-proven to be effective, the mechanical solutions may require well logs to detect the water entry point in the well. Chemical methods may present environment risks. In this study, an alternative method, Downhole Water Sink, is proposed to solve the problem of unwanted water production from a casing or tubing leak. The effectiveness of this method to control water production in a well with casing or tubing leaks is tested using the Hele-Shaw experimental model. The results show that this method can control unwanted water production via dynamic control of the pressure drawdown in the reservoir. From a technical standpoint, the advantage of this technology is that it eliminates the need to run logs to locate the water entry point and does not require chemical injection into the formation. From an environmental standpoint, this technology has the circular economy elements. Because the produced water in this technology contains little or no oil, it can be reused for reinjection into the reservoir for water flooding or pressure maintenance purposes. Therefore, a production-reinjection process to recycle the produced water is established to reduce the pollution caused by discharging the wastewater into the environment.
套管或油管泄漏会导致油井产出不必要的水。许多化学和机械控水技术可用于解决此问题，包括将化学堵水液挤入目标区域，或使用封隔器、水泥、桥塞、补丁来封堵泄漏。尽管这些方法在现场已被证明是有效的，但机械解决方案可能需要测井来检测井中的水进入点。化学方法可能存在环境风险。在本研究中，提出了一种替代方法，即井下集水坑，以解决套管或油管泄漏导致的不必要的水产出问题。使用赫莱肖（Hele-Shaw）实验模型测试了该方法控制套管或油管泄漏井中产水的有效性。结果表明，该方法可以通过控制储层压降的动态来控制不必要的产水。从技术角度来看，这项技术的优势在于它不需要进行测井来定位水进入点，也不需要向地层注入化学物质。从环境角度来看，这项技术具有循环经济要素。因为该技术产生的水中几乎不含油，因此可以重复用于注水或压力维持目的的回注到储层中。因此，建立了一种生产-回注工艺来回收产出水，以减少将废水排放到环境中造成的污染。
