System for increasing efficiency of chemical treatment
AssigneeOryx Energy Company
InventorsG. N. Bass, Carl D. McBride, Greg Maddux, John L. Cayias, Johnny M. Reinschmidt, Kurt P. McCaslin
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Abstract
Apparatus and method for decreasing chemical requirements for chemicals injected into a stream a low concentrations, such as for dehydration of crude oil, are provided. An algorithm is used to provide a signal to decrease chemical injection rate of a variable rate pump if the water content of the treated oil has not exceeded a preset value in a preset time and to increase chemical injection rate if the water content of the treated oil is exceeded within a preset time. The algorithm allows the control system to learn from previous experience.
Claims25
(amended) Apparatus for controlling the rate of chemical injection into a stream, the chemical being used to control a measurable variable, comprising:
- means for measuring the variable controlled by the chemical;
- means for comparing the variable controlled with a preset value;
- means for timing to determine the number of time units since the variable exceeded the preset value;
- and
- means for producing a control signal for adjusting the chemical injection rate according to an algorithm based on the number of time units since the variable exceeded the preset value.
Apparatus for controlling the rate of chemical injection into a crude oil stream flowing through a dehydration facility having a dehydration vessel comprising:
- means for measuring water content in the treated crude oil effluent from the dehydration vessel;
- means for comparing the water content of the effluent crude oil to a preset value;
- means for measuring flow rate of crude oil through the dehydration vessel;
- means for timing for determining the number of time units since the water content value exceeded the preset value;
- and
- means for producing a control signal for adjusting the chemical injection rate according to an algorithm based on the number of time units since water content value exceeded the preset value and the flow rate of crude oil through the dehydration vessel.
A computer-implemented method for changing a signal to control the rate of chemical injection into a stream, the chemical being used to control a measurable variable, comprising:
- measuring the variable to be controlled by the chemical;
- comparing the measured values of the variable to be controlled with a preset value;
- when the measured value of the variable does not exceed the preset value, determining the number of time units since the variable exceeded the preset value;
- applying an algorithm which changes the signal such as to decrease the rate of chemical injection in response to the amount of time since the variable exceeded the preset value, and when the measured value of the variable exceeds the preset value applying an algorithm which changes the signal such as to increase the rate of chemical injection.
A computer-implemented method for controlling the rate of chemical injection into a crude oil dehydration facility having a dehydration vessel comprising:
- providing the computer with a data base defining the relationship between a base rate of chemical injection and flow rate of crude oil through the dehydration facility;
- measuring the flow rate of crude oil through the facility;
- repetitively performing in the computer a calculation of base rate of chemical injection;
- initiating in the computer a timer which increments at preset amounts of real time;
- employing the number of increments of the timer in an algorithm to calculate an economizer function having a value less than 1.0;
- repetitively multiplying in the computer the base rate of chemical injection by the economizer function to calculate an adjusted rate of chemical injection;
- and
- supplying a signal to a variable rate pump to pump chemical at the adjusted rate.
Dependencies are inferred from the claim text.