老盐井组井型互换再利用工程实践

Interchange of well types in the old salt mining well set for reuse

摘要:

水平钻井连通水溶采卤一直是开采井矿盐资源最常用和最经济有效的手段，但由于地层条件复杂、饱和卤水结晶、套管破损等因素造成盐井组采卤运行过程中通道堵塞，一直是制约盐井组运行年限的主要原因。近些年，对堵塞井组修治常用方法有憋压、通井、开窗侧钻，其中水平井开窗侧钻重新对接现有溶腔在很多盐田区块修井中被广泛应用。在河北宁晋石盐田Y2-Y4井组修井过程中，存在老溶腔无法再利用的情况，此时老溶腔成为井组二次对接的“累赘”。在该区块首次采用井组井型互换（水平井改直井，直井改水平井）的方法，避开了老溶腔，实现了老井组的再利用。

Abstract:

Solution mining with intersected wells by horizontal drilling technology has always been the most commonly used and economic and effective means for mining salt resources. However， the salt mining well set is prone to the channel blockage in the process of brine extraction due to the complex formation conditions， saturated brine crystallization， casing damage and other factors，which restricts the service life of the horizontally connected salt well set. In recent years， the commonly used methods for the repair and treatment of blocked well sets are pressurizing， scraping， and window milling. Among them， window milling from horizontal wells is widely used for workover in many salt field blocks. During workover of Well Set Y2-Y4 at Shiyantian， Ningjin， Hebei province， it was found the existing mining cavern can not be reused， and was an obstacle for the second-time intersection of the well set. It was the first time that the two wells were switched in type （changing horizontal well into vertical well and vertical well into horizontal well） to by-pass the existing cavern to realize the reuse of the old well set in this block.