不同类型孔缝约束下煤粉运移与沉降可视化分析  

Visualization analysis of coal fine migration and settlement under different types of pore-fracture

作　　者：王博洋 崔云飞 王千 丁延 李耿 潘武杰 WANG Boyang;CUI Yunfei;WANG Qian;DING Yan;LI Geng;PAN Wujie(Institute of Unconventional Oil and Gas,Northeast Petroleum University,Daqing 163318,China;School of Resources and Geosciences,China University of Mining and Technology,Xuzhou 221008,China;School of Resources and Environmental Engineering,Inner Mongolia University of Technology,Hohhot 010051,China)

机构地区：[1]东北石油大学非常规油气研究院,黑龙江大庆163318 [2]中国矿业大学资源与地球科学学院,江苏徐州221116 [3]内蒙古工业大学资源与环境工程学院,内蒙古呼和浩特010051

出　　处：《煤炭科学技术》2024年第S2期294-311,共18页Coal Science and Technology

基　　金：国家自然科学基金资助项目(42472196,42002186)。

摘　　要：以煤粉为主的固相颗粒产出问题贯穿整个煤层气开发过程,产生的储层伤害是导致产能衰减与生产成本增高的重要诱因之一。当前差异流体作用与不同类型孔缝约束下煤粉悬浮、运移、沉降规律及机制尚不明确,制约了煤层气连续稳定排采和高效开发。基于此,以煤粉产出已显著影响气井产能的保德区块为研究对象,借助3D打印技术加工不同孔缝类型及其组合的毫米尺度模型样品,依托自主研发的评价煤粉运移、沉降的试验装置,揭示不同类型孔缝及其组合约束下差异流体作用对煤粉运移的影响机制。结果表明:在相同流体作用条件下,煤粉运移由易到难依次为平行板状孔缝、圆柱形孔缝与细颈瓶孔缝;对于孔缝组合而言,圆柱形孔缝(入口端)+细颈瓶孔缝+平行板状孔缝(出口段)的组合比圆柱形孔缝(入口端)+平行板状孔缝+细颈瓶孔缝(出口段)的组合有更好的抵抗煤粉沉降导致储层物性变差的能力。孔径越大,煤粉利于运移产出而不利于沉降;NaHCO3溶液矿化度越高,水解产生的阴离子OH-使煤粉颗粒表面负电荷增加,能够缓解煤粉聚集效果,有利于煤粉产出。流体的力学作用与化学作用共同决定煤粉运移诱导煤储层伤害程度。The production of solid particles mainly composed of"coal fine"runs through the entire process of coalbed methane development,and the resulting reservoir damage is one of the important factors leading to production capacity decline and increased production costs.At present,the laws and mechanisms of coal fine suspension,migration,and settlement under differential fluid action and different types of pore-fracture constraints are not yet clear,which restricts the continuous and stable discharge and efficient development of coalbed methane.Based on this,this paper took the Baode block,where coal fine production has significantly affected well productivity,as the research object.The millimeter sized model samples of different pore types and their combinations was established using 3D printing technology.With the help of independently developed experimental devices for evaluating coal fine transport and settlement,the mechanism of the influence of differential fluid action on coal fine transport under different types of pores and their combination constraints was revealed.The results indicated that under the same fluid action conditions,the order of coal fine migration from easy to difficult is parallel plate shaped pore-fracture,cylindrical pore-fracture,and thin neck bottle pore-fracture.The combination of cylindrical pore-fracture(inlet end),thin necked bottle pore-fracture,and parallel plate shaped pore-fracture(outlet section)has a better ability to resist the deterioration of reservoir properties caused by coal fine deposition than the combination of cylindrical pore-fracture(inlet end),parallel plate shaped pore-fracture,and thin necked bottle pore-fracture(outlet section).The larger the pore size,the more favorable the coal fine is for transportation and production,but not for sedimentation.The higher the mineralization degree of NaHCO3 solution,the anion OH-generated by hydrolysis increases the negative charge on the surface of coal fine particles,which can alleviate the aggregation effect and facilitate coal

关 键 词：煤粉 3D打印 流体作用 储层伤害 孔缝类型 

分 类 号：TE258[石油与天然气工程—油气井工程]