摘要
井口脉冲加压是注完水泥后给密闭的环空施加水力脉冲压力,利用流体的微可压缩性使环空水泥浆处于上下往复活动状态来改善水泥浆凝固特性,达到提高水泥胶结质量的目的。以流体力学为基础,建立了井口脉冲压力在环空中的衰减规律及环空流体在脉冲压力作用下运动幅度的理论模型,研究了脉冲压力幅度、水泥浆初切力和环空流体压缩系数与环空中脉冲压力衰减程度和流体运动幅度的关系。分析表明,216 mm的井眼内下入139.7 mm的套管,采用常规水泥浆体系,2 MPa的脉冲压力可传播距离达4100 m,通过施加较小的压力脉冲可使环空水泥浆往复运动,破坏水泥浆的胶凝结构,消除水泥浆因体积和化学收缩形成的微孔隙和胶结面中微环隙,对提高固井质量具有重要作用,该项研究可为脉冲加压装置的设计与参数优化提供理论依据。
The principle of wellhead pressure pulsation technology is to pressurize the sealed annular with hydraulic pulse pressure,the annular cement slurry will then keep moving up and down due to the micro-compressibility of the fluid,and the cement bond quality can thus be improved.Based on the hydrodynamics,the attenuation rule of the wellhead pulse pressure along the annular is established,and also the movement amplitude of the annular fluid is found,and the relationships between the pulsation pressure amplitude,gel strength of the slurry and the compressibility factor of annular fluid with pulse pressure attenuation rate and fluid movement amplitude. The analysis made in the paper shows pulse pressure can be transmitted about 4100 meters in a ф216 mm well running ф139.7 mm casing strings with common cement slurries with a pulsate pressure of 2 MPa.The annular cement slurry can move up and down under a small pulse pressure,the gel structure can then be destroyed,and the microholes resulted from the volumetric or chemical shrinkage or formed within the bond interfaces can be decreased or even eliminated,the cementing quality will then be improved.This study will provide theoretic basis for design of pulse pressure device and parameter optimization.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2007年第2期57-59,共3页
Natural Gas Industry
基金
中国石化集团公司项目(编号:JP01022)资助
关键词
固井
注水泥
脉冲压力
水泥浆
传播模型
环空
加压装置
cementing,cement injection,pulse pressure,cement slurry,transmitting model,annular space,pressurizing device
