套管微小漏失综合测漏方法及其现场应用

Comprehensive Detectable Method of Mini-leakage in Casing and Its Application

综合利用自然伽马、磁定位、温度计、流量计、多臂井径及磁测井等测量仪器,在压裂车稳定注水打压及稳压条件下结合定点及持续测量方式测量油水井中流量及微差井温变化,综合寻找套管漏失点准确位置。当漏失量较大时,可通过定点打压测量流量以确定可疑漏失井段,再通过稳压连续测量确定确切漏失点位置,提高了测漏的时效;当漏失量较小时可在稳压条件下,连续向下测量微差井温,在微差井温异常点上下打压测量流量变化验证该异常;微差井温拐点可以精确确定漏失点位置,但并非所有温差变化均可以解释为套管漏失,漏失点的确定需要综合上下测量点流量变化及不同测速下流量曲线综合判断。将该综合测漏的新思路应用于现场测漏作业中已经取得初步成功。

Due to the failure of the pressure test,the oil well cannot go into operation as usual,and the water well cannot be injected as usual,either.It is of great significance to find out the position of oil casing leakage accurately and fastly in the oilfield production.We integrate natural gamma,magnetic orientation,thermometer,flow rate,MIT and MTT logging tool under the conditions of stable compression of water injection and stable pressure to monitor the flow and thermometer change of the oil-water well by fixed-point and continuous measurement so to synthetically look for the position of leakage points.If the leakage is heavy,the suspicious depth interval can be confirmed by the fixed-point flow measurement,and then leakage point position can be determined by continuously measuring differential temperature curve to improve measuring efficiency.If the leakage is tiny,it can be detected by continuous downward measuring differential temperature under the condition of stable pressure,then,the abnormal points can be tested by measuring the change of flow at up-and-down differential temperature abnormal point.Knee points of differential temperature can be used to determine the position of leakage point accurately,but not all of the differential temperature changes could be interpreted as oil casing leakage.Leakage point can only be determined by comprehensive measurements of point flow and the flow curve at different speeds.The method achieved preliminary effect in practice application.