| 摘要: |
| 对垂直井筒不同水气比和含砂体积分数下的气水砂三相流动机制及气水携砂能力进行系统的试验研究。通过试验得到单相气体携砂和气水携砂临界流速与砂粒径的定量关系和规律。根据试验数据揭示的气液携砂机制,建立不产水和产水气井的临界携砂流速模型,用于预测给定生产条件下的携砂条件和携砂能力,并提出考虑井筒携砂的新型气井综合协调曲线用于实际气井工况分析和制度调整。结果表明:一旦气井见水,气井携砂能力将比不产水条件下严重降低,气体流速和水气比是控制携砂动态的主要因素;随着水气比从零开始升高,流型依次为无携砂现象的泥状流、具有携砂能力的环雾流、段塞流,以及其他相同水气比条件下的气水两相流型;气液两相流要达到携砂条件,气体流速必须达到携液流速,并且液相流速要达到基本的单相液体携砂条件。 |
| 关键词: 产水气井 出砂 气液固三相流动 携砂能力 携砂机制 |
| DOI：10.3969/j.issn.1673-5005.2014.06.014 |
| 分类号::TE 375 |
| 基金项目:国家自然科学基金项目(51374226);中国石油天然气股份有限公司重大科技专项(2011E-0309) |
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| Experimental study on mechanism and capability of sand-carrying in water-producing gas wells and its application |
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DONG Changyin1, CHEN Xin an1, A Xueqing2, CHEN Yu1, KANG Ruixin2, FENG Shengli2
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(1.School of Petroleum Engineering in China University of Petroleum, Qingdao 266580, China;2.Research Institute of Drilling and Production Engineering, Qinghai Oilfield, PetroChina, Dunhuang 736200, China)
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| Abstract: |
| The gas-liquid-solid multi-phase flow in vertical wells was experimentally simulated to study the mechanism and capability of sand-carrying for gas wells with water production, in which the effects of gas and water flow rate, water-gas ratio (WGR) and sand volume fraction were investigated. Based on experimental results, the critical gas flow rate for sand-carrying and the relationship between the size of sands and gas and water flow rate were obtained. A sand-carrying evaluation model for gas well with and without water production was developed. The model can be used to predict the critical gas flow rate for sand-carrying with various sand sizes and the maximum sand rate that can be carried by gas at a certain flow rate. A new integrated coordination chart was figured out for the evaluation of sand-carrying capability in gas wells with water and sand production. The results show that, once the well starts to produce water, its sand-carrying capability will be reduced compared with that no water production. Gas flow rate and WGR are the dominant factors affecting the flow mechanism. As the WGR increases, different flow patterns tend to appear in wellbore in sequence, including mud-gas flow without sand-carrying capability, annular and plug flows with sand-carrying capability, similar to the flow patterns observed in normal gas-liquid two phase flow with the same WGR. The prerequisite for sand-carrying in gas wells with water producing is that high gas flow rate is needed to make or carry water flow at sufficiently high velocity for sands to start moving upward. |
| Key words: water-producing gas well sand production gas-liquid-solid three-phase flow sand-carrying capability sand-carrying mechanism |
