亏空层水泥塞封堵能力实验研究

Experimental Study on the Sealing Capacity of Cement Plug in Deficit Layer

水泥塞是油气井隔离储层或其他含流体地层的一道重要屏障,水泥浆能否有效封固多个不同渗透率地层,亟须开展实验研究确认,以指导弃井精细化设计。通过自主设计实验方法与装置,模拟常规水泥浆、韧性水泥浆以及膨胀水泥浆在3~10 MPa压差作用下分别进入75×10^(-3)、300×10^(-3)、750×10^(-3)、2 000×10^(-3)μm^(2)不同渗透率地层的情况。实验结果表明:不同水泥浆类型、不同渗透率地层、在不同压差条件下挤水泥,水泥浆只能在井壁形成滤饼,不能进入地层。通过将该研究成果应用于亏空层弃井及固井设计中,现场作业按设计顺利施工。该实验研究成果为指导亏空层弃井及固井精细化设计提供了依据。

Cement plug is an important barrier to the oil and gas well isolation reservoir or other fluid-containing formation.Whether the cement slurry can effectively seal multiple different penetration layers urgently needs to carry out experimental research confirmation to guide the fine design of abandoned wells.Through the independent design of the experimental method and device,the researchers simulated the situations of different permeability formations when the conventional cement slurry,toughness cement slurry,and expansion cement slurry entered formations of 75×10^(-3)μm^(2)/300×10^(-3)m2μm^(2)/2000×10^(-3)μm^(2) under the action of 3 to 10 MPa pressure difference.According to the experiment,the cement is squeezed under the conditions of different cement slurry types,different permeability formation,and different pressure difierences,and the cement slurry can only form a filter cake on the wall of the well and cannot enter the formation.Through the application of research results to the design of abandoned well in deficit layer and the cementing program,the onsite operation was smoothly constructed according to the design.The experimental research results provide a basis for guiding the fine design of abandoned well and cementing in deficit layer.