Method to Optimize Production from a Gas-lifted Oil Well

Abstract

A method for determining and reporting a general production state of a gas-lift system for an oil well, the oil well having associated tubing, casing, and gas-lift valves, and wherein sensor signals from the welt and its associated tubing and casing are input into mathematical models. The method comprises the steps of: a) extracting values from the mathematical models that indicate instantaneous states of production; b) supplying the sensor signals and the values to an associative memory agent; and c) using the associative memory agent to associate the sensor signals and the values to generate the general production state.

1 . A method for determining and reporting a general production state of a gas-lift system for an oil well, the oil well having associated tubing, casing, and gas-lift valves, and wherein sensor signals from the well and its associated tubing and casing are input into mathematical models, the method comprising the steps of:
 a. extracting values from the mathematical models that indicate instantaneous states of production;   b. supplying the sensor signals and the values to an associative memory agent; and   c. using the associative memory agent to associate the sensor signals and the values to generate the general production state.   
   
   
       2 . The method according to  claim 1 , wherein the operation of the associative memory agent comprises pattern recognition and use of knowledge of past well behaviors. 
   
   
       3 . The method according to  claim 1 , wherein the step of extracting values includes a step of deducing instantaneous states of the gas-lift valves by using the mathematical models. 
   
   
       4 . The method according to  claim 2 , wherein the step of associating uses probabilistic classification to generate the general production state. 
   
   
       5 . The method according to  claim 3 , wherein the step of deducing includes determining if abnormal conditions exist based on the received sensor signals, and wherein an associative memory agent is used to make the determination. 
   
   
       6 . The method according to  claim 3 , further comprising, after the step of generating the general production state, the step of reporting the general production state. 
   
   
       7 . The method according to  claim 5 , wherein the step of determining if abnormal conditions exist uses a Finite Fourier Transform combined with ordered statistics. 
   
   
       8 . A system for diagnosing problems in, and reporting the general state of, the production mode of the gas-lift operations on a well, the well having associated gas-lift valves and sensors, the system comprising:
 a. a personal computer for receiving reports of signals from the sensors;   b. means stored on the personal computer for generating mathematical models to deduce the states of the gas-lift valves and the states of the production mode by using as inputs both the sensor signals and a knowledge base, to generate multiple states over time of the production mode;   c. an associative memory agent stored on the personal computer, and responsive to the multiple states, for detecting and aggregating anomalies, and for reporting a general state of the production mode.   
   
   
       9 . The system of  claim 8 , wherein the associative memory agent learns well behaviors for the specific conditions of a particular well, and diagnoses gas injection and production problems in the well based on pattern recognition and past well behaviors.