陇东地区油田套管腐蚀破损与洛河组沉积相的关系研究

鄂尔多斯盆地陇东油田套管腐蚀破损严重地影响着油田生产,白垩系洛河组的Na2SO4型地层水与套管之间的电化学、生物化学反应是主要原因。笔者研究发现全盆稳定分布的洛河组沙漠相砂体具有均质性、渗透性强的特点,为地下水的补给、径流和排泄提供了良好的通道和空间,形成的强渗流场加速了套管腐蚀破损速度,并通过分析证实本地区仅依靠提高固井质量来防止套管腐蚀破损是不够的,必须通过新材料、新技术、新工艺的突破性大量应用才能解决这一难题。

Relation between sedimentary facies of the Luohe Formation in the Changqing Oilfield, Longdong, and casing corrosion and damage

In the Longdong area, Changqing oilfield, Ordos, casing corrosion and damage influence oil production seriously. The main cause is thought to be electrochemical and biochemical reactions between casing and formation water of Na2SO4 type in the Cretaceous Luohe Formation. The desert-facies sandstone of the Luohe Formation distributed uniformly in the whole basin is characterized by high permeability and homogeneity, so it can provide good conduits and spaces for the recharge, runoff and discharge of groundwater and the resulting strong leakage field accelerates casing corrosion and damage. Analysis confirms that only relying on raising the quality of casing and cementing is not enough to prevent casing corrosion and damage in the study area, and only by using new materials and technologies can we solve this problem.