冀中坳陷大城凸起深部煤层气井垢形成机理及防垢方法  

Scale Formation Mechanism and Anti-scale Method of Deep Coalbed Methane Wells in Dacheng Uplift of Jizhong Depression

作　　者：姜燕 张利文 张嘉友 于根喜 JIANG Yan;ZHANG Liwen;ZHANG Jiayou;YU Genxi(Oil and gas technology Research Institute,Huabei Oilfield Company,PetroChina,Hebei 062550;Erlian branch of Huabei Oilfield Company,PetroChina,Inner Mongolia 026000)

机构地区：[1]中国石油华北油田公司油气工艺研究院,河北062550 [2]中国石油华北油田公司二连分公司,内蒙古026000

出　　处：《中国煤层气》2024年第3期38-42,共5页China Coalbed Methane

摘　　要：为解决大城深部煤层气井因井筒结垢严重导致检泵周期较短问题,研究基于煤层气井水质和结垢物成分分析。结果显示,深部煤层气井地层水中富含HCO_(3)^(-)离子,易产生碳酸盐垢的金属阳离子;结垢物主要成分为FeCO_(3)、铁氧化物以及少量的CaCO_(3)、MgCO_(3)等;指出压力、流速是影响煤层气井结垢主要因素;提出煤层井结垢机理为排采诱导流体压力降低导致二氧化碳从水中大量析出所致,而铁氧化物主要由HCO_(3)^(-)离子对金属Fe腐蚀产生。针对大城煤层气井结垢机理和地质特点,提出了内衬油管和定期加药综合治理防垢方法,为深部煤层气高效稳定开发提供了重要支撑。To address the issue of short pump maintenance cycles caused by serious shaft scaling in coal-bed methane wells of Dacheng,a study is conducted based on the analysis of the produced water quality and scaling composition in coalbed methane wells.The results indicate that the formation water in deep coalbed methane wells is rich in HCO_(3)^(-)ions,which are easy to form carbonate scales with metal cations.The main components of the scale are FeCO_(3),iron oxide and small amounts of CaCO_(3),MgCO_(3),etc.It is identified that pressure and flow rate are the primary factors influencing scaling in coalbed methane wells.The scaling mechanism is attributed to the decrease of fluid pressure induced by drainage,leading to the precipitation of large amounts of CO_(2),from the water,while iron oxides are primarily produced by the cor-rosion of metal Fe by HCO_(3)^(-)ions.Based on the scaling mechanism and geological characteristics of coal-bed methane wells in Dacheng,a comprehensive treatment method of lining oil pipes and regular dosing is proposed to prevent scaling,which has been preliminarily validated.This provides crucial support for the efficient and stable development of deep coalbed methane reservoirs.

关 键 词：大城 深层 煤层气 结垢 机理 防垢 

分 类 号：TE37[石油与天然气工程—油气田开发工程]