Automated initial shut-in pressure estimation
AssigneeConocoPhillips Company
InventorHerbert W. SWAN
Life of this patent
Estimating the term…
Abstract
Water hammer is oscillatory pressure behavior in a wellbore resulting from the inertial effect of flowing fluid being subjected to an abrupt change in velocity. It is commonly observed at the end of large-scale hydraulic fracturing treatments after fluid injection is rapidly terminated. Factors affecting treatment-related water hammer behavior are disclosed and field studies are introduced correlating water hammer characteristics to fracture intensity and well productivity.
Claims14
A method for completing a hydrocarbon well in a shallow reservoir where the process comprises:
- installing a wellbore in a shallow hydrocarbon reservoir;
- calculating a waterhammer period for a perforation depth;
- calculating a sampling frequency to capture a waterhammer period;
- sealing the wellbore;
- fracturing the wellbore by increasing pump pressure;
- shutting off the pump pressure;
- and
- performing a water hammer sensitivity analysis comprising:
- identification of the shut-in period;
- identification of water hammer peaks and troughs;
- calculation of water hammer period and the number of periods;
- and calculation of water hammer decay rate.
A method for fracturing a hydrocarbon well in a shallow reservoir where the process comprises:
- sealing a hydrocarbon wellbore;
- fracturing the wellbore by increasing pump pressure;
- shutting off the pump pressure;
- identification of the shut-in period;
- identification of water hammer peaks and troughs
- calculation of water hammer period and the number of periods;
- and calculation of water hammer decay rate;
- and
- calculating the instantaneous shut-in pressure (ISIP);
- and identifying one or more fracturing patterns from ISIP signature.
A method for improving hydrocarbon production from a shallow reservoir where the process comprises:
- sealing a hydrocarbon wellbore;
- fracturing the wellbore by increasing pump pressure;
- shutting off the pump pressure;
- identification of the shut-in period;
- identification of water hammer peaks and troughs;
- calculation of water hammer period and the number of periods;
- and calculation of water hammer decay rate;
- and
- calculating the instantaneous shut-in pressure (ISIP);
- identifying one or more fracturing patterns from ISIP signature;
- and
- improving well productivity from said shallow reservoir.
Dependencies are inferred from the claim text.