金秋区块气田水回注增注措施

Augmented injection measure for Jinqiu block gas field water

川中油气矿金秋区块气田水在回注过程中出现注水困难的现象,现阶段的回注污水仅经过自然沉降和普通过滤,需要对水质特征进行分析,针对性地提出增注措施。借助X射线荧光(XRF)、X射线衍射(XRD)、扫描电镜等手段对回注污水进行分析,发现金秋区块回注污水铁含量高,仅普通过滤不能除去污水中的Fe2+,Fe2+与氧接触后还会产生Fe3+沉淀。另外,该区块污水矿化度高、易结垢、腐蚀性强。建议金秋区块的气田水处理流程加设锰砂除铁装置,同时加入适量阻垢剂和缓蚀剂。岩心动态实验表明,锰砂除铁后污水的回注能力大幅提高。

There are some difficulties in water injection in Jinqiu block gas field of Central Si- chuan Oil and Gas District. The recycled produced water has only been taken natural sedimenta tion and ordinary filtration at present. The characteristic of water quality need to be analyzed and the measures of augmented injection should be put forward. This paper analyzed the recycled pro- duced water by using X-ray fluorescence （XRF）, X-ray diffraction （XRD） and scanning electron microscope（SEM）, and found out that the Jinqiu block recycled produced water contain high iron content, Fe2＋ of which could not be removed by ordinary filtering only, and it contacts with oxy- gen to produce ferric iron precipitation. In addition, sewage from this block presents high salini- ty, easy fouling and strong corrosiveness. So the Jinqiu block gas field water treatment process should add manganese sand iron removal device, while put into proper amount of scale inhibitor and corrosion inhibitor. Dynamic core experiment showed that sewage reinjection ability was greatly improved after iron removal.