| CPC E21B 47/06 (2013.01) [E21B 2200/20 (2020.05)] | 15 Claims |
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1. A system for identifying shut-ins of a well, the system comprising a controller that is configured to:
obtain a plurality of raw pressure values measured by a sensor device located toward a bottom hole of the well and captured over a period of time, wherein each of the plurality of raw pressure values indicates a pressure at the bottom hole of the well during the period of time;
apply, using a filter module of the controller and in real time, a plurality of filters to the plurality of raw pressure values to generate a plurality of filtered pressure values;
identify, using a sequence identification module of the controller and in real time, a plurality of initial sequences comprising monotonically trending values among the plurality of filtered pressure values, wherein each of the plurality of initial sequences comprises a start point and an end point;
splice, using a splicing module of the controller and in real time, adjacent initial sequences among the plurality of initial sequences, wherein the splicing module joins the end point of a prior adjacent initial sequence with the start point of a subsequent adjacent initial sequence into a single initial sequence when the prior adjacent initial sequence has a slope that is greater than that of the subsequent adjacent initial sequence;
adjust, in real time, the start point of at least one of a plurality of final initial sequences based on derivatives of the filtered pressure values, wherein the plurality of final initial sequences comprises the single initial sequence after splicing and the plurality of initial sequences without splicing;
apply, in real time, a parametric function to the plurality of final initial sequences to generate a plurality of fitted sequences, wherein the plurality of fitted sequences comprises the plurality of final initial sequences excluding final initial sequences falling outside a tolerance of the parametric function; and
apply, in real time, pattern recognition to the plurality of fitted sequences to generate a plurality of final sequences, wherein the plurality of final sequences comprises the plurality of fitted sequences excluding fitted sequences falling outside a tolerance of the pattern recognition, wherein the plurality of final sequences captures an actual shut-in event and omits a false positive indication of a shut-in event, and wherein the plurality of final sequences is used in real time for at least one of a group consisting of modifying petroleum engineering workflows that are used to characterize productivity of the well, modifying surveillance, analysis and optimization of the well, and satisfying regulatory and reporting requirements related to the well.
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