疏松砂岩油气藏出砂风险及机理离散元分析  

Discrete element analysis on sand production risk and mechanism in unconsolidated sandstone oil and gas reservoir

作　　者：赵博 苏亚中[2] 丛巍[2] 孙恒博[2] 董晓渊 胡铭寰 李岳 ZHAO Bo;SU Yazhong;CONG Wei;SUN Hengbo;DONG Xiaoyuan;HU Minghuan;LI Yue(Oil Industry Training Centre,China University of Petroleum (East China),Qingdao Shandong 266580,China;NO.1 Oil Production Plant of Qinghai Oilfield,Haixi Qinghai 817000,China)

机构地区：[1]中国石油大学(华东)石油工业训练中心,山东青岛266580 [2]青海油田采油一厂,青海海西817000

出　　处：《中国安全生产科学技术》2020年第11期59-65,共7页Journal of Safety Science and Technology

基　　金：国家重点研发计划项目(2016YFC0304005);国家重点基础研究发展计划项目(2015CB251201)。

摘　　要：为了进一步了解疏松砂岩储层开发过程中的出砂机理,基于PFC3D平台构建离散元模型用于分析疏松砂岩储层出砂风险,探究生产压差等因素对地层出砂的影响。结果表明:较高生产压差下地层流体流速较快,流体对砂粒的拖曳力较大,出砂较严重,生产压差为4.5 MPa时出砂量比3.0,1.5 MPa分别高34.86%和75.45%;地层流体黏度的升高会降低其对砂粒的拖曳,一定程度上减弱出砂程度,流体黏度在1000 mPa·s时出砂量比100,10 mPa·s下分别低42.50%和54.27%;较大地应力差异条件下砂粒间相互作用较强,砂粒更易脱离岩石骨架而出砂,地应力差异系数为1.75时出砂量是1.25时的2.51倍;另外,内聚力较低的储层砂粒间黏聚力较低,相同生产条件下更易出砂。研究结果可用于预测疏松砂岩储层出砂及定制防砂方案。In order to further understand the sand production mechanism during the development of unconsolidated sandstone reservoir,a discrete element model for analyzing the risk of sand production in the f unconsolidated sandstone reservoirs was constructed on the basis of PFC3D platform,and the influence of production pressure difference and other factors on the sand production of stratum was explored.The results showed that when the production pressure difference was high,the formation fluid velocity was faster,the drag force of fluid on the sand particles was larger,and the sand production was more serious.When the production pressure difference was 4.5 MPa,the sand production amount was 34.68%and 75.45%higher than that when the production pressure difference was 3.0 MPa and 1.5 MPa,respectively.The increase of formation fluid viscosity would reduce its drag force on the sand particles and weaken the sand production degree to a certain extent,and when the fluid viscosity was 1000 mPa·s,the sand production amount was 42.50%and 54.27%lower than that when the fluid viscosity was 100 mPa·s and 10 mPa·s,respectively.Under the condition of larger ground stress difference,the interaction between sand particles was stronger,so the sand particles were easier to break away from the rock skeleton and produce sand,and when the ground stress difference coefficient was 1.75,the sand production amount was 2.51 times that when the ground stress difference coefficient was 1.25;In addition,the reservoir with lower cohesion had the lower adhesion between sand particles and was easier to produce sand under the same production conditions.The research results can provide references for predicting the sand production in unconsolidated sandstone reservoirs and customizing the sand prevention schemes.

关 键 词：疏松砂岩 出砂 离散元 生产压差 流体黏度 内聚力 数值模拟 

分 类 号：X937[环境科学与工程—安全科学] TE357[石油与天然气工程—油气田开发工程]