Applying Radial Acoustic Amplitude Signals To Predict Intervals of Sand-Stuck Tubing

摘要

The reuse of existing well bores is one cost savingtechnique employed by oil and gas producers in maturefields. This process usually requires the removal oftubing and packers to allow the well to be deepened orside-tracked. The tubing removal process is often madedifficult due to its being stuck inside casing due tomechanical binding, or binding caused by dehydratedmud or sand in the annulus between the tubing andcasing. Conventional direct and indirect methods offinding the stuck point(s) along an interval of tubing,such as Free Point Indicator Tools or AcousticAttenuation measurements, have proven themselvesuseful in finding the point(s) where the tubing is stuck.However, when the sticking is due to uncompacted sandthat has entered the annular space between the tubingand casing, these conventional stuck pipe indicationmethods are often inconclusive.Technological advancements in the design anddevelopment of slim, 1-11/16 in. OD, radial cement bondtools allow the application of a new measurement to findsand-stuck tubing intervals. These tools provide up to sixindependent, short-spaced, acoustic attenuationmeasurements distributed radially around the tool body.When recorded inside tubing, their increased sensitivityto sound attenuation, as compared to conventional omni-directionalamplitude signals, allows sand intervals alongthe outside of the tubing to be distinguished fromintervals where little or no sand is present. Thisinformation is used to select the best depth to sever orback-off the free tubing in order to reduce the intervallength and expense associated with the washoverprocess required to remove the remaining tubing fromthe wellbore.An overview of conventional stuck pipe recoverytechniques is discussed along with a brief explanation ofapplied acoustic technology. A case example of a SouthLouisiana well is presented to demonstrate theapplication and illustrate the cost savings gained by useof this newest technology.