水平井油气水砂多相复杂流动规律研究

Moderate sanding production of horizontal well is a kind of effective technology for the development of the unconsolidated sandstone reservoirs. The sand carrying flow in the wellbore is key link between the downhole sand-prevention and sand-seperation at the wellhead. It is important to research the complex flow law in horizontal wellbore for the optimization of the sand-prevention methods and the sand-prevention parameters. Unfortunately the research which was reported for oil-gas-water-sand multiphase flow mechanics is limited. In this research, a set of multifunction experiment equipment for multiphase flow simulation in complex structure well which was designed and manufactured by the Chinese University of Petroleum will be used for the multiphase experiments in horizontal well and the flow law in different section(vertical section, deviated section and horizontal section) of the well will be revealed. The method of differentiating the different flow pattern will be researched. The influence of the contents of the fluid, the fluid viscosity, the fluid density etc. on the flow pattern will be researched accordingly. In addition, a sand carrying ability prediction model will be established on account of the wellbore size, the sand size, the sand density and so on. The results of the whole research will provide scientific foundation for the accurate prediction of the sand carrying ability and sand prevention optimization design during the moderated sanding production in horizontal well in unconsolidated sandstone reservoirs.

水平井结合适度出砂开采是我国开发海上疏松砂岩稠油油藏的有效技术，其中井筒携砂流动是衔接井下防砂和井口地面脱砂的必要环节，深入研究水平井油气水砂复杂流动规律是优化防砂方法及防砂参数（避免井壁失稳且保障油井产能）和确定井口含砂量的重要保障。据调研目前有关水平井全井段油气水砂多相复杂流动尚未见文献报道。本项研究利用自主研制的复杂结构井多功能井筒多相流动模拟实验装置开展水平井全井段油气水砂复杂流动实验，分别针对水平井不同井段（直井段、斜井段、水平段）的不同流动状态进行流型划分，揭示油气水三相含量、原油粘度、原油密度、油气水三相流速等因素对流型的影响规律；建立不同流型条件下不同井段的携砂能力预测模型，研究井眼尺寸、砂粒尺寸、砂粒密度等因素对携砂能力的影响规律，确定井口产出液中的含砂浓度。为我国海上稠油油藏水平井适度出开采过程中携砂能力的准确预测及防砂完井整体优化设计提供科学依据。

水平井结合适度出砂开采是我国开发海上疏松砂岩稠油油藏的有效技术，其中井筒携砂流动是衔接井下防砂和井口地面脱砂的必要环节，深入研究水平井油气水砂复杂流动规律是优化防砂方法及防砂参数（避免井壁失稳且保障油井产能）和确定井口含砂量的重要保障。.本研究在前人研究工作的基础上利用自主研制的复杂结构井多功能井筒多相流动模拟实验装置开展水平井全井段油气水砂复杂流动实验，分别针对水平井不同井段（直井段、斜井段、水平段）的不同流动状态进行流型划分，揭示油气水三相含量、原油粘度、原油密度、油气水三相流速等因素对流型的影响规律；建立不同流型条件下不同井段的携砂能力预测模型，研究井眼尺寸、砂粒尺寸、砂粒密度等因素对携砂能力的影响规律，确定井口产出液中的含砂浓度。取得了以下主要成果；.1）基于大尺寸井筒多相复杂流动物理模拟实验装置，开展了稠油-水两相携砂目标段流动实验，获得了井筒压降及砂床高度的变化规律，并绘制了稠油-水两相携砂井筒复杂流动流型图版。.2）针对固液两相流动，研究了流体粘度、阻力系数、干涉沉降速度等随固相含量的变化规律，构建了固-液混合粘度模型、流动阻力系数模型与固相干涉沉降速度相关模型，模型误差小于20%，。.3）基于多相流体力学中的多流体模型、均相流模型及实验观测结果，构建了考虑砂床流体流动所产生的附加压降的稠油水两相携砂井筒复杂流动油水砂分层流动、分散流动模型。.4）基于油气水砂多相流动物理模拟实验装置，开展了稠油气水三相携砂井筒复杂流动条件下的井筒压降规律及携砂能力预测研究，给出了油气水三相携砂流动实验流型图版，并分析了气相流量、液相流量等参数对井筒压降规律及携砂能力的影响规律。