Drum Load Monitoring

Abstract

An assembly for monitoring load on a drum during an operation in a well with a well access line deployed from the drum. The assembly may include multiple line detection mechanisms for acquiring real-time information relative to dynamic characteristics of the lone over the course of the operation. The assembly also includes a processor for computing the real-time information in light of pre-stored information relative to physical characteristics of the line and the drum. As a result, real-time monitoring of a load on the drum may be achieved. Thus, the operation may be adjusted in real-time as necessary to avoid over-loading of the drum. Additionally, a drum load history may be recorded so as to better account for the true condition of the drum following successive operations.

1 . An assembly for monitoring a load on a drum, the assembly comprising:
 a line length detection mechanism coupled to a line deployable from the drum to detect a length of the line relative to the drum;   a line tension detection mechanism coupled to the line to detect tension on the line; and   a processor having pre-loaded drum and line characteristic data stored thereon and coupled to said line detection mechanisms to obtain line length and line tension data therefrom, said processor configured to run a computation of the pre-loaded data and the obtained line data for the monitoring.   
     
     
         2 . The assembly of  claim 1  wherein the drum characteristic data comprises one of drum material, drum architecture, drum dimensions, and drum history. 
     
     
         3 . The assembly of  claim 1  wherein the line characteristic data comprises at least one of an amount of the line on the drum, a tension profile of the line, a diameter of the line, a stretch profile of the line, and line history. 
     
     
         4 . The assembly of  claim 1  wherein said line tension detection mechanism comprises a strain gauge based detector. 
     
     
         5 . The assembly of  claim 1  further comprising downhole equipment coupled to a downhole end of the well access line. 
     
     
         6 . The assembly of  claim 5  wherein said line tension detection mechanism is incorporated into one of said line length detection mechanism and said downhole equipment. 
     
     
         7 . The assembly of  claim 1  wherein the drum comprises a core to accommodate the line coupled to a flange for retaining the line about the core. 
     
     
         8 . The assembly of  claim 7  wherein the load comprises one of vertical pressure directed at the core and horizontal pressure directed at the flange. 
     
     
         9 . The assembly of  claim 8  wherein the computation supports a dimensionally mapped representation of the pressures. 
     
     
         10 . An assembly for delivering downhole equipment to a well at an oilfield, the assembly comprising:
 a drum for positioning at the oilfield adjacent the well;   a well access line coupled to said drum for accessing the well with the downhole equipment;   a line length detection mechanism for positioning at the oilfield for interfacing said well access line to meter an amount thereof in the well;   a line tension detection mechanism coupled to said well access line to monitor a tension thereof; and   a processor having a pre-loaded drum and line characteristic data stored thereon and coupled to said mechanisms to acquire information relative to the metered amount and the monitored tension, said processor configured to run a computation of the pre-loaded characteristic data and the acquired information for real-time monitoring of load on the drum.   
     
     
         11 . The assembly of  claim 10  wherein said well access line is a wireline cable. 
     
     
         12 . The assembly of  claim 10  wherein the downhole equipment comprises a logging tool secured to the well access line. 
     
     
         13 . The assembly of  claim 10  wherein the well is of a deviated character. 
     
     
         14 . A method of monitoring a load on a drum accommodating a line for access to a well, the method comprising:
 storing pre-loaded drum and line information on a processor, the information indicative of physical characteristics of the drum and line;   positioning the line within the well;   acquiring line information during said positioning, the line information indicative of dynamic characteristics of the line; and   employing the processor to compute the load on the drum in real-time during said positioning from the pre-loaded information and the acquired information.   
     
     
         15 . The method of  claim 14  wherein the dynamic characteristics comprise line length and tension. 
     
     
         16 . The method of  claim 14  further comprising adjusting a rate of said positioning based on the computed load. 
     
     
         17 . The method of  claim 14  further comprising halting said positioning based on a computed load in excess of a predetermined load on the drum. 
     
     
         18 . A method comprising:
 employing a drum to provide a well access line to a well;   monitoring a load on the drum in real-time during said employing; and   maintaining a load history of said monitoring.   
     
     
         19 . The method of  claim 18  wherein said monitoring comprises:
 storing pre-loaded information on a processor relative to physical characteristics of the drum and the well access line; 
 acquiring dynamic information relative to the line during said employing; and 
 computing the load in real-time during said employing based on the pre-loaded information and the dynamic information. 
 
     
     
         20 . The method of  claim 18  wherein said maintaining comprises:
 establishing a record of the load; and 
 labeling the drum for association with the record. 
 
     
     
         21 . The method of  claim 18  wherein said maintaining comprises:
 storing at least the load history on a memory device attached to the drum.