井斜角对固井一界面泥膜形成规律的影响

Effect of Deviation Angle on Formation Law of Mud Film at Cementing-casing Interface

固井一界面胶结质量对油气井生产过程中环空气窜和环空带压问题具有重要影响,而套管表面形成的泥膜质量与分布情况则尤为关键。针对油气井井斜角大小不同导致形成泥膜的差异性,自主建立了一种模拟不同井斜角下套管表面泥膜形成规律的实验装置和方法,实验研究了井斜角对固井一界面泥膜形成规律的影响。研究结果表明:当井斜角为0°时,泥膜厚度由上到下依次变厚,同时沿套管方向,横向呈环状分布;当井斜角介于0°～90°时,套管上下面的泥膜厚度大于两侧,并且沿套管方向泥膜分布呈近似线状;当井斜角为90°时,上下面的泥膜厚度大于两侧的泥膜厚度,同时套管两侧面出现了不同程度的无泥膜覆盖区域。研究结果可对提高固井一界面胶结质量和防止环空气窜和环空带压问题提供科学依据和技术支撑。

The cementing quality of cement-casing interface has an important influence onannulus gas channeling and annulus pressure in the production process of oil and gas wells, while the quality and distribution of the mud film formed on the surface of the casing is particularly critical. Aiming at the difference of the formation of mud film caused by the deviation angle of oil and gas wells, an self-constructed experimental device and method are established for simulating the formation law of mud film on the casing surface under different deviation angle. The effect of deviation angle on the formation law of mud film at cement-casing interface was studied experimentally. The analysis shows that when the deviation angle is 0°, the mud film thickness becomes thicker from top to bottom, and it is distributed in a circular shape along the direction of the casing. When the deviation angle is between 0 and 90°,the mud film thickness on the upper and lower sides of the casing is larger than the two sides, and the distribution of the mud film along the casing direction is approximately linear. When the deviation angle is 90°, the mud films thickness on the upper and lower is greater than the mud film thickness on both sides, and different degrees of mud-free coverage areas appear on both sides of the casing. The research results can provide scientific basis and technical support for improving cementation quality of cement-casing interface and preventing annulus gas channeling and annulus pressure problems.