Inferring wellsite operations from power consumption measurements

Abstract

A surface rig system includes components that consume power (e.g., using electrical motors). The power consumption of the components is monitored and used to infer other operational parameters. Illustratively, power consumption (e.g., current draw) of a shale shaker is monitored and used to infer: the volume of cuttings on the screen; changes in fluid viscosity, density, or rheology; health of the shaker screen; fluid cycle times; or screen clogging/blinding. Power consumption of pumps, fluid agitators, draw works, and other devices can also be monitored and used to infer parameters such as: fluid viscosity, density or rheology; hook load, or fluid slugging. Based on inferred parameters, changes may be made or advised for operation of equipment, including a shale shaker, downhole tool, pump, shaker screen, top drive, drilling fluid, or draw works.

What is claimed is: 
     
         1 . A method for inferring cuttings properties from a wellbore, comprising:
 performing a drilling operation;   separating cuttings from drilling fluid using a separation element;   monitoring power consumed by the separation element while separating the cuttings; and   using the power consumed by the separation element, inferring one or more properties of the cuttings.   
     
     
         2 . The method of  claim 1 , wherein separating the cuttings includes separating the cuttings from the drilling fluid using a shale shaker. 
     
     
         3 . The method of  claim 1 , wherein inferring the one or more properties of cuttings includes inferring a mass of the cuttings. 
     
     
         4 . The method of  claim 1 , further comprising:
 in response to inferring the one or more properties of the cuttings, controlling a surface or downhole parameter.   
     
     
         5 . The method of  claim 4 , wherein controlling the surface or downhole parameter includes at least one of balancing cuttings load between multiple separation elements, balancing fluid volume between multiple separation elements, balancing power consumption between multiple separation elements, changing an oscillation of the separation element, changing a screen angle of the separation element, fluid flushing a screen of the separation elements, changing weight-on-bit, changing rotational speed, changing fluid flow rate, changing fluid density, changing drill pipe acceleration or deceleration during tripping, diverting fluid from the separation element, changing a fluid treatment plan, or generating an alarm. 
     
     
         6 . The method of  claim 1 , wherein inferring the one or more properties of the cuttings includes using a calibration model. 
     
     
         7 . The method of  claim 6 , wherein the calibration model is based at least partially on at least one of cuttings mass to power consumption, power consumption without cuttings, power consumption before fluid treatment, screen angle, screen beach, fluid viscosity, fluid density, or fluid flow rate. 
     
     
         8 . The method of  claim 1 , wherein the separation element is a shale shaker and the one or more properties includes a cuttings mass, the method further comprising:
 measuring cuttings mass using a mass-based cuttings flow meter or cuttings volume machine vision system; and   cross-correlating the measured cuttings mass with the power consumed by the shale shaker.   
     
     
         9 . A system for inferring operational parameters at a wellsite, comprising:
 a drilling system configured to perform drilling activities that generate cuttings;   a shale shaker;   a motor powering the shale shaker; and   a processor and memory, the memory including instructions which, when accessed by the processor, cause the processor to:
 measure a power consumption of the motor while the shale shaker separates the cuttings from drilling fluid; and 
 based on the power consumption of the motor, determine a mass of cuttings separated by the shale shaker. 
   
     
     
         10 . The system of  claim 9 , wherein the instructions further cause the processor to compare the mass of the cuttings to an expected mass of cuttings. 
     
     
         11 . The system of  claim 10 , wherein the instructions further cause the processor to determine the expected mass of cuttings based on at least one of wellbore diameter, section length, or formation type. 
     
     
         12 . The system of  claim 10 , wherein, when the mass of the cuttings is less than the expected mass of cuttings, the instructions further cause the processor to instruct the drilling system to change a drilling parameter. 
     
     
         13 . The system of  claim 10 , wherein, when the mass of cuttings is greater than the expected mass of cuttings, the instructions further cause the processor to identify whether the mass of cuttings is greater than the expected mass of cuttings due to a difference in density of the cuttings. 
     
     
         14 . The system of  claim 10 , wherein measuring the power consumption includes measuring a current draw of the motor. 
     
     
         15 . A method for inferring cuttings properties from a wellbore, comprising:
 measuring a first power consumption of one or more shale shakers with a known mass and density of cuttings;   measuring a second power consumption of the one or more shale shakers with wellbore cuttings from a wellbore; and   based on the first power consumption and the second power consumption, determining a wellbore mass of the wellbore cuttings.   
     
     
         16 . The method of  claim 15 , wherein measuring the first power consumption includes measuring the first power consumption based on a known drilling fluid density, and further comprising determining a fluid density of drilling fluid with the wellbore cuttings. 
     
     
         17 . The method of  claim 15 , further comprising, based on the wellbore mass of the wellbore cuttings, determining whether there are cuttings remaining in the wellbore. 
     
     
         18 . The method of  claim 17 , wherein, when there are cuttings remaining in the wellbore, further comprising taking a control measure that flushes out cuttings remaining in the wellbore. 
     
     
         19 . The method of  claim 15 , wherein the one or more shale shakers includes a first shale shaker and a second shale shaker and determining the wellbore mass of the wellbore cuttings includes determining a first wellbore mass associated with the first shale shaker and a second wellbore mass associated with the second shale shaker. 
     
     
         20 . The method of  claim 19 , wherein, when the first wellbore mass is different than the second wellbore mass, applying a control measure that balances the first wellbore mass with the second wellbore mass.