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US 10,132,493 B2Granted
Steam generation apparatus and associated control system and methods for providing desired steam quality
AssigneeSkavis Corporation
InventorsRandall J. Davis, Charles F. Noll, Jr.
Life of this patent
Estimating the term…
Abstract
The current disclosure relates to steam generation and supply apparati and associated control systems. Particularly, the current disclosure relates to such steam generation supply apparati and associated control systems that are used for enhanced oil recovery. Certain embodiments are provided including methods and associated control systems related to the startup as well as main steam pressure header control or maintenance of a desired steam quality for such steam generation systems during normal operation.
Claims19
A method comprising:
- determining a feedwater enthalpy and a feedwater flow rate by at least one device in a steam generation and supply apparatus configured to extract oil from a formation, the apparatus comprising a feedwater supply system and a steam generation system;
- setting, in a control system of the apparatus, a desired steam quality of at least one of water and steam supplied by the steam generation system;
- estimating, by at least one other device in the apparatus, a target steam enthalpy of the at least one of water and steam supplied by the steam generation system;
- and
- automatically adjusting, by a programmable controller of the apparatus, a firing rate of a burner configured to supply heat to a boiler in the steam generation system, the automatic adjusting executed responsive to a determination of a heat input rate based at least partially upon the target steam enthalpy;
- wherein automatically adjusting the firing rate of the burner maintains the at least one of water and steam supplied by the steam generation system at the desired steam quality, allowing more heat to be pumped into an injection well and raising a number of units of oil produced from an oil well per unit heat put into a steam injection well, as compared to oil extraction systems lacking capability to automatically adjust a burner firing rate.
3 more elements
A method comprising the steps of:
- determining a feedwater enthalpy and a feedwater flow rate by at least one device in a steam generation and supply apparatus configured to extract oil from a formation, the apparatus comprising a feedwater supply system and a steam generation system;
- determining, by at least one other device in the apparatus, a pressure of at least one of water and steam supplied by the steam generation system;
- setting, in a control system of the apparatus, a desired steam quality of the at least one of water and steam supplied by the steam generation system;
- estimating, by at least one other device in the apparatus, a target steam enthalpy of the at least one of water and steam supplied by the steam generation system by
- determining current enthalpies of vapor and liquid of the at least one of water and steam,
- looking up values of the current enthalpies of the vapor and liquid from a table that comprises enthalpy values for vapor and liquid listed by pressure, and
- multiplying the desired steam quality in fraction form by a difference of the current enthalpies of the vapor and liquid and adding a product of that calculation to the current enthalpy of liquid being generated by the steam generation system;
- and
- automatically adjusting, by a programmable controller of the apparatus, a firing rate of a burner configured to supply heat to a boiler in the steam generation system, the automatic adjusting executed responsive to a determination of a heat input rate based at least partially upon the target steam enthalpy;
- wherein automatically adjusting the firing rate of the burner maintains the at least one of water and steam supplied by the steam generation system at the desired steam quality, allowing more heat to be pumped into an injection well and raising a number of units of oil produced from an oil well per unit heat put into the injection well, as compared to oil extraction systems lacking capability to automatically adjust a burner firing rate.
7 more elements
A method comprising the steps of:
- determining a feedwater enthalpy and a feedwater flow rate by at least one device in a steam generation and supply apparatus configured to extract oil from a formation, the apparatus comprising a feedwater supply system and a steam generation system;
- setting, in a control system of the apparatus, a desired steam quality of at least one of water and steam supplied by the steam generation system;
- estimating, by at least one other device in the apparatus, a target steam enthalpy of the at least one of water and steam supplied by the steam generation system;
- automatically adjusting, by a programmable controller of the apparatus, a firing rate of a burner configured to supply heat to a boiler in the steam generation system, the automatic adjusting executed responsive to a determination of a heat input rate based at least partially upon the target steam enthalpy;
- wherein the boiler comprises a flue that comprises an instrument for measuring how much oxygen is present in a flue gas in the flue;
- determining whether an oxygen content of the flue gas is within an acceptable range defined between 1.5% and 25%;
- and
- assuming a value of 3% if the oxygen content is outside of the range of 1.5% and 25%;
- wherein automatically adjusting the firing rate of the burner maintains the at least one of water and steam supplied by the steam generation system at the desired steam quality, allowing more heat to be pumped into an injection well and raising a number of units of oil produced from an oil well per unit heat put into the injection well, as compared to oil extraction systems lacking capability to automatically adjust a burner firing rate.
6 more elements
A method comprising the steps of:
- determining a feedwater enthalpy and a feedwater flow rate by at least one device in a steam generation and supply apparatus configured to extract oil from a formation, the apparatus comprising a feedwater supply system and a steam generation system;
- setting, in a control system of the apparatus, a desired steam quality of at least one of water and steam supplied by the steam generation system;
- estimating, by at least one other device in the apparatus, a target steam enthalpy of the at least one of water and steam supplied by the steam generation system;
- automatically adjusting, by a programmable controller of the apparatus, a firing rate of a burner configured to supply heat to a boiler in the steam generation system, the automatic adjusting executed responsive to a determination of a heat input rate based at least partially upon the target steam enthalpy;
- wherein the boiler comprises
- a flue that comprises an instrument for measuring how much oxygen is present in a flue gas in the flue, and
- a thermocouple for measuring a stack temperature of the boiler;
- determining whether an oxygen content of the flue gas is within an acceptable range;
- determining whether the stack temperature is within acceptable parameters defined by a high limit of 550 degrees F;
- and
- assuming that the stack temperature is 480 degrees F when the stack temperature measures above 480 degrees F;
- wherein automatically adjusting the firing rate of the burner maintains the at least one of water and steam supplied by the steam generation system at the desired steam quality, allowing more heat to be pumped into an injection well and raising a number of units of oil produced from an oil well per unit heat put into the injection well, as compared to oil extraction systems lacking capability to automatically adjust a burner firing rate.
9 more elements
Dependencies are inferred from the claim text.