Advanced perforation modeling
View Patent ↗A technique is provided for modeling flow simulations at downhole reservoir conditions and rock formations after performing wellbore perforations. By utilizing these flow simulations, a user may be able to simulate and compare different scenarios, thereby facilitating a more effective, profitable, and realistic choice of perforating systems and operating conditions.
1. A method of perforating a wellbore in a subterranean formation, the method comprising the steps of:
accessing a data log of wellbore parameters, the wellbore parameters including porosity data collected at intervals along the wellbore;
calculating a rock penetration value at the intervals along the wellbore, based on (i) experimental rock penetration data, (ii) a given explosive weight associated with a gun system, and (iii) the porosity data of the wellbore;
determining a clear tunnel value associated with the rock penetration value, at the intervals along the wellbore, based on (1) a bottom-hole pressure condition of the wellbore, (2) the calculated rock penetration value, and (3) the porosity data;
determining expected fluid flows, at the intervals along the wellbore, based on the calculated rock penetration value and the clear tunnel value;
comparing the expected fluid flows determined at a range of the intervals, for plural perforating gun systems;
selecting a perforating gun system from the plural perforating gun systems for the wellbore, based on the step of comparing;
lowering the selected perforating gun system inside a casing that lines the wellbore; and
perforating the casing and the wellbore by detonating explosive charges of the selected perforating gun system so that a fluid flows from the subterranean formation into the casing through holes made in the casing by the explosive charges.
2. The method of claim 1 , wherein the bottom-hole pressure condition is underbalanced.
3. The method of claim 1 , wherein the bottom-hole pressure condition is overbalanced.
4. The method of claim 1 , wherein determining the rock penetration value comprises interpolating or extrapolating the experimental rock penetration value based on the given explosive weight and the porosity data.
5. The method of claim 1 , wherein the clear tunnel value reflects an actual tunnel that is opened for flow by a shaped charge.
6. The method of claim 1 , wherein determining the clear tunnel value is obtained from interpolation or extrapolation of experimental clear tunnel measurements obtained from stressed rock tests.
7. A method of perforating a wellbore in a subterranean formation, the method comprising:
collecting porosity data at given intervals along the wellbore during drilling;
calculating a rock penetration value, at the given intervals, based on (i) experimental rock penetration data, (ii) a given explosive weight associated with a gun system, and (iii) the porosity data of the wellbore;
determining a clear tunnel value associated with the rock penetration value, at the intervals along the wellbore, based on (1) a bottom-hole pressure condition of the wellbore, (2) the calculated rock penetration value, and (3) the porosity data;
determining expected fluid flows, between the subterranean formation and the wellbore, at the intervals along the wellbore, based on the calculated rock penetration value and the clear tunnel value;
selecting a perforating gun system from the plural perforating gun systems for the wellbore, based on the expected fluid flows;
lowering the selected perforating gun system inside a casing that lines the wellbore; and
perforating the casing and the wellbore by detonating explosive charges of the selected perforating gun system so that a fluid flows from the subterranean formation into the casing through holes made in the casing by the explosive charges.
8. The method of claim 7 , wherein the bottom-hole pressure condition is underbalanced.
9. The method of claim 7 , wherein the bottom-hole pressure condition is overbalanced.
10. The method of claim 7 , wherein determining the rock penetration value comprises interpolating or extrapolating the experimental rock penetration value based on the given explosive weight and the porosity data.
11. The method of claim 7 , wherein the clear tunnel value reflects an actual tunnel that is opened for flow by a shaped charge.
12. The method of claim 7 , wherein determining the clear tunnel value is obtained from interpolation or extrapolation of experimental clear tunnel measurements obtained from stressed rock tests.