1. A method for hydraulic fracture characterization using microseismic datapoints comprising:
identifying the principle strike orientations of the average microseismic datapoints that relate to one or more sets of planes and their orientation uncertainty using a computer processor;
determining the dip of each set of planes considering a contact weight between each microseismic datapoint and each plane within each set of planes;
determining the location of each plane within each set of planes; and
performing a statistical analysis for each set of planes with a common principle strike orientation to determine an uncertainty related to an orientation, spacing and dip of a respective set of subsurface fractures.
2. The method of claim 1, further comprising identifying a location of all microseismic datapoints.
3. The method of claim 2, further comprising setting an initial orientation for a plane, the initial orientation comprising a strike angle and a dip angle.
4. The method of claim 3, wherein the principal strike orientations of the average microseismic datapoints that relate to one or more sets of planes and their orientation uncertainty are identified by:
creating the plane that has a normal vector and passes through the average location of all microseismic datapoints for the orientation of the plane;
calculating a perpendicular distance between each microseismic datapoint and the plane;
creating a set of planes parallel to the plane wherein each plane in the set of planes intersects a volume represented by a location uncertainty of each microseismic datapoint;
counting the number of planes in the set of planes and the number of microseismic datapoints that contact the planes in the set of planes;
calculating the average microseismic datapoints that contact each plane in the set of planes for each orientation of the planes in the set of planes;
incrementing the strike angle or the dip angle of the plane by 1 degree; and
repeating each of the prior steps until the strike angle equals 0 degrees or 360 degrees and the dip angle equals 0 degrees or 90 degrees.
5. The method of claim 4, wherein the dip angle for each set of planes and the location of each plane within each set of planes is determined by:
repeating each step in claim 4 at each of the principal orientations for each respective dip angle;
identifying the plane from each set of planes created that has a maximum number of microseismic datapoint intersections and its location;
calculating a contact weight between the plane with the maximum number of microseismic datapoint intersections and the microseismic datapoints;
removing the microseismic datapoints that contact the plane with the maximum number of microseismic datapoint intersections; and
repeating each of the prior steps until there is no plane with the maximum number of microseismic datapoint intersections that contacts three or more microseismic datapoints.
6. The method of claim 1, wherein the orientation uncertainty of the one or more sets of planes is determined by performing a Monte Carlo statistical analysis.
7. The method of claim 5, wherein the uncertainty related to the orientation, spacing and dip of each respective set of subsurface fractures is calculated considering the contact weight for each set of planes and the microseismic datapoints that are related to each set of planes.
8. The method of claim 5, wherein the contact weight is based upon the location uncertainty of each microseismic datapoint, the perpendicular distance between each microseismic datapoint and the plane and a numerical weighted value that represents a moment magnitude associated with each microseismic datapoint.
9. The method of claim 5, wherein the contact weight is assigned to each respective microseismic datapoint.
10. The method of claim 1, further comprising displaying the statistical analysis.
11. A non-transitory program carrier device tangibly carrying computer executable instructions for hydraulic fracture characterization using microseismic datapoints, the instructions being executable to implement:
identifying the principle strike orientations of the average microseismic datapoints that relate to one or more sets of planes and their orientation uncertainty;
determining the dip of each set of planes considering a contact weight between each microseismic datapoint and each plane within each set of planes;
determining the location of each plane within each set of planes; and
performing a statistical analysis for each set of planes with a common principle strike orientation to determine an uncertainty related to an orientation, spacing and dip of a respective set of subsurface fractures.
12. The program carrier device of claim 11, further comprising identifying a location of all microseismic datapoints.
13. The program carrier device of claim 12, further comprising setting an initial orientation for a plane, the initial orientation comprising a strike angle and a dip angle.
14. The program carrier device of claim 13, wherein the principal strike orientations of the average microseismic datapoints that relate to one or more sets of planes and their orientation uncertainty are identified by:
creating the plane that has a normal vector and passes through the average location of all microseismic datapoints for the orientation of the plane;
calculating a perpendicular distance between each microseismic datapoint and the plane;
creating a set of planes parallel to the plane wherein each plane in the set of plane intersects a volume represented by a location uncertainty of each microseismic datapoint;
counting the number of planes in the set of planes and the number of microseismic datapoints that contact the planes in the set of planes;
calculating the average microseismic datapoints that contact each plane in the set of planes for each orientation of the planes in the set of planes;
incrementing the strike angle or the dip angle of the plane by 1 degree; and
repeating each of the prior steps until the strike angle equals 0 degrees or 360 degrees and the dip angle equals 0 degrees or 90 degrees.
15. The program carrier device of claim 14, wherein the dip angle for each set of planes and the location of each plane within each set of planes is determined by:
repeating each step in claim 14 at each of the principal orientations for each respective dip angle;
identifying the plane from each set of planes created that has a maximum number of microseismic datapoint intersections and its location;
calculating a contact weight between the plane with the maximum number of microseismic datapoint intersections and the microseismic datapoints;
removing the microseismic datapoints that contact the plane with the maximum number of microseismic datapoint intersections; and
repeating each of the prior steps until there is no plane with the maximum number of microseismic datapoint intersections that contacts three or more microseismic datapoints.
16. The program carrier device of claim 11, wherein the orientation uncertainty of the one or more sets of planes is determined by performing a Monte Carlo statistical analysis.
17. The program carrier device of claim 15, wherein the uncertainty related to the orientation, spacing and dip of each respective set of subsurface fractures is calculated considering the contact weight for each set of planes and the microseismic datapoints that are related to each set of planes.
18. The program carrier device of claim 15, wherein the contact weight is based upon the location uncertainty of each microseismic datapoint, the perpendicular distance between each microseismic datapoint and the plane and a numerical weighted value that represents a moment magnitude associated with each microseismic datapoint.
19. The program carrier device of claim 15, wherein the contact weight is assigned to each respective microseismic datapoint.
20. The program carrier device of claim 11, further comprising displaying the statistical analysis.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. In a communication system comprising at least a first and second simulcast station at a first remote site, a method comprising:
detecting unavailability of the first simulcast station for communicating on a first communication resource;
determining if the second simulcast station is available for supporting simulcast transmissions on the first communication resource, and
if the second simulcast station is available, assigning the second simulcast station to communicate on the first communication resource.
2. The method of claim 1 further comprising:
communicating, by the second simulcast station, simulcast messages on the first communication resource.
3. The method of claim 2 wherein the steps of detecting, determining and assigning are performed by a simulcast site controller.
4. The method of claim 3 wherein the step of detecting is accomplished by the simulcast site controller failing to receive a response to a message sent to the first simulcast station.
5. The method of claim 3 wherein the communication system further comprises a comparator adapted for sending data to be communicated over the simulcast channel to one or more of the simulcast stations along with a timestamp specifying when the data will be transmitted.
6. The method of claim 5 wherein the step of detecting is accomplished by the first simulcast station notifying the comparator of a malfunction and the comparator notifying the simulcast site controller of the malfunction.
7. The method of claim 5 wherein the step of detecting is accomplished by the comparator notifying the simulcast site controller of a failure of the comparator to receive a response from a message sent by the comparator to the first simulcast station.
8. The method of claim 5 wherein the communication system further comprises a plurality of simulcast stations distributed among a plurality of remote sites and where subset of the plurality of simulcast stations communicate on the first communication resource and wherein the controller, comparator and simulcast stations are connected by an Internet Protocol network and the simulcast stations that communicate on the first communication resource share a multicast Internet Protocol address.
9. The method of claim 8 wherein the step of assigning is accomplished by sending an Internet Protocol packet to the second simulcast station containing the multicast Internet Protocol address of the simulcast stations that communicate on the first communication resource.
10. The method of claim 8 further comprising the step of sending, by the simulcast site controller, an Internet Protocol packet instructing the first simulcast station to shut down.
11. The method of claim 5 wherein the unavailability of the first simulcast station is due to a problem with the connection between the first simulcast station and the comparator.
12. The method of claim 3 wherein the communication system further comprises a third and fourth simulcast station at a second remote site, the method further comprising:
detecting, by the simulcast site controller, the unavailability of the third simulcast station communicating on the first communication resource at the second remote site;
determining, by the simulcast site controller, if the fourth simulcast station is available for supporting simulcast communication on the first communication resource and, if the fourth simulcast station is available;
assigning, by the simulcast site controller, the fourth simulcast station to communicate on the first communication resource; and
communicating, by the fourth simulcast station, simulcast messages on the first communication resource.
13. The method of claim 1 wherein the unavailability of the first simulcast station is due to a malfunction of the first simulcast station.
14. In a wireless communication system employing simulcast communication, a method for initiating simulcast communication in a simulcast site, the simulcast site comprising a plurality of remote sites, the method comprising:
determining availability of a plurality of simulcast stations located at the plurality of remote sites;
assigning, by a simulcast site controller, members of a first simulcast channel, the members comprising respective first-available simulcast stations at each of the remote sites; and
performing simulcast communication using the first simulcast channel.
15. The method of claim 14 wherein the first simulcast channel is used for communication of control information.
16. The method of claim 14 further comprising:
assigning, by the simulcast site controller, members of a second simulcast channel, the members comprising respective second-available simulcast stations at each of the remote sites; and
commencing simulcast communication using the second simulcast channel.
17. The method of claim 16 wherein the second simulcast channel is a payload channel.
18. In a communication system employing simulcast transmissions by a simulcast site, the simulcast site comprising a simulcast site controller and a plurality of remote sites, each remote site having a plurality of simulcast stations, a method comprising:
detecting, by the simulcast site controller, unavailability of a first simulcast station of the plurality of simulcast station at a first remote site of the plurality of remote sites for communicating on a first communication resource;
determining, by the simulcast site controller, if there is a second simulcast station of the plurality of simulcast stations at the first site that is available for supporting simulcast transmissions on the first communication resource, and if the second simulcast station is available;
assigning, by the simulcast site controller, the second simulcast station to communicate on the first communication resource.
19. The method of claim 18 further comprising:
communicating, by the second simulcast station, simulcast messages on the first communication resource.