新疆某油田油井堵塞物成分及成因分析

Analysis on Components and Origin of the Well Blockage in One Xinjiang Oilfield

吴文明 侯吉瑞

WUWenming HOU Jirui

针对新疆某油田开发过程中出现油井堵塞的难题，选取了具有代表性的X-5 原油作为研究对象，研究了原油的组分组成以及该油井井口、井筒堵塞物的主要成分，并分析堵塞物形成原因，进一步分析了X-5 原油、井口堵塞物、井筒堵塞物3 种样品中沥青质的平均结构，并分析了X-5 原油的析蜡沉积特性。研究表明：X-5 原油的稳 定性较差，原油中的沥青质易发生聚沉。原油、井口堵塞物、井筒堵塞物中沥青质的芳碳率依次增大，分别为0.46、0.52 和0.65。原油中芳碳率越高的沥青质越容易发生缔合和聚沉。原油中芳碳率高的沥青质会自发缔合而在井筒中形成以沥青质为主的井筒堵塞物；芳碳率稍低的沥青质，不易形成聚沉物，但会和砂石作用共同作用在井口形成堵塞物。油井出砂与沥青质沉积是导致井口与井筒中堵塞的关键因素，此外蜡沉积也是造成油井堵塞的原因之一。

In order to solve the blockage problem during the oilfield development，the representative X-5 crude oil in one Xinjiang oilfield was studied. The components of the crude oil and the blockage in both wellhead and wellbore were also studied to analyze the origin of blockage. The average structure of asphaltenes derived from crude oil，wellhead blockage and wellbore blockage were all measured，and the evolution of wax deposits for X-5 crude oil was further analyzed. It was shown that the stability of X-5 crude oil was poor and the asphaltene was easy to get aggregated and deposited. The aromatic carbon ratio（fA）of the asphaltenes derived from crude oil，wellhead blockage or wellbore blockage increased successively，which was 0.46，0.52 and 0.65，respectively. It was supposed that the asphaltenes with higher fA in crude oil were easier to aggregate and deposit. Consequently，the wellbore blockages mainly consisted of asphaltenes with higher fA. The asphaltene with lower fA was hard to form precipitates，however，it could form blockages with the participation of sand. The sand and the deposited asphaltene in oil wells were the key factors leading to blockage in the wellhead and wellbore. In addition，the wax deposits also led to the blockage of oil well.

10.19346/j.cnki.1000-4092.2022.02.027