油井产出状态下测井找漏工艺方法的研究及应用

Research and application of leakage detection technology by logging in the output state of oil wells

常规套损井找漏方法主要包括封隔器分段封堵试压法和井温剖面找漏法。以上两种方法均根据破漏段吸水的原理找漏,优点是直观,且能准确掌握破漏段吸水状况。但对于部分油井井筒缩径变形、存在多个漏点或吸水启动压力高的漏点(现场生产过程中出现的"只出不进"现象)采用以上两种方法均无法准确找出漏点位置,且采用高压挤水极易造成套管的二次损伤和地层伤害。为此,根据油井测量产液剖面的原理,设计了产出剖面状态下测井找漏工艺和解释方法,并在沙20-31等井进行了应用,均成功找出了具体破漏段位置,为后期措施提供了有力保障。其中沙20-31井措施后增储、增产效果显著。

The leakage detection methods for conventional casing-damaged wells are packer staged blocking pressure test and well temperature profile method for leakage detection. The above two methods both work by the principle of water sucking of damaged and leaked segment, with the advantage of intuitive and accurate grasp of water sucking situation of damaged and leaked segment. However, when it comes to the oil wells with deformed shaft due to hole shrinkage, more than one leakage point or the leakage point with high water sucking threshold pressure （the phenomenon of ＂only in, no out＂ in field production）, the two methods no longer prove accurate in detecting leakage, adding that high pressure water squeezing shall cause second damage to casing and formation damage. Against the problem, based on the principle of profile detection of liquid output, the leakage detection method by logging in output profile state and interpretation method are designed. Application in well Sha20-31 and other wells has proved a success in detecting the detailed location of damage and leakage, providing forceful guarantee for later operations. What＇s more, well Sha20-31 witnesses apparent effects in reserve increase and output rise after the operation.