Method, system and apparatus for black oil delumping

#The subject matter of this specification relates to a method, including an associated system or apparatus and computer program and program storage device, for Black Oil Delumping that is used to convert wellstreams from a black oil simulation into their constituent components when a compositional representation of the wellstreams is required.

#Black oil reservoir simulation still has wide application in the petroleum industry because it is computationally far less demanding than compositional simulation. However, a principal limitation of black oil reservoir simulation is that it does not provide detailed compositional information necessary for surface process modeling. Black oil delumping overcomes this limitation by converting a black oil wellstream into a compositional wellstream thereby enabling the composition and component molar rates of a production well in a black oil reservoir simulation to be reconstituted. This specification discloses a comprehensive black oil delumping method based primarily on the compositional information generated in a depletion process that is used initially to provide data for the black oil simulation in a typical workflow. Examples disclosed in this specification show the accuracy of this method in different depletion processes including: natural depletion, water injection, and gas injection. The specification also presents a technique for accurately applying the black oil delumping method to wells encountering crossflow.

#One aspect of the present invention involves a method for black oil delumping, comprising: converting a black oil wellstream into a compositional wellstream thereby enabling a set of composition and component molar rates of a production well in a black oil reservoir simulation to be reconstituted.

#A full understanding will be obtained from the detailed description presented hereinbelow, and the accompanying drawings which are given by way of illustration only and are not intended to be limitative to any extent, and wherein:

#FIG. 1 illustrates a general purpose multi-platform reservoir and network coupling controller in a coupled reservoir/network system adapted for analyzing a pressure interaction between a reservoir and a constrained surface facility network or for predicting the behavior of several fields, which may have different fluid compositions, sharing a common surface facility;

#FIG. 2 illustrates the reservoir and network coupling controller of FIG. 1, where the controller includes a Black Oil Delumping Software adapted for practicing a Black Oil Delumping method that is used to convert wellstreams from a black oil simulation into their constituent components when a compositional representation of the wellstreams is required;

#Referring to FIG. 1, a general purpose multi-platform reservoir and network coupling controller 10 in a coupled reservoir/network system 12, representing an integrated surface and subsurface modeling system 12, is illustrated. The coupling controller 10 is adapted for analyzing a pressure interaction between a reservoir simulator 16 and a constrained surface facility network 14 or for predicting a behavior of several reservoir fields which may have different fluid compositions and share a common surface facility. The reservoir and network coupling controller 10 in the coupled reservoir/network system 12 of FIG. 1 is fully described and set forth in International Publication number WO2004/049216 A1, published Jun. 10, 2004, based on International Application number PCT/US2002/037658 filed Nov. 23, 2002, the disclosure of which is incorporated by reference into the specification of this application.

#The ‘Controller’ 10 is a ‘Field Management’ system, and its task is to apply time-dependent controls and operations on the production and injection wells in one or more reservoir simulation models. In addition to the reservoir simulation models, the controller 10 may also communicate with one or more surface facility models 14 (such as a pipeline network model), since conditions on this part of the integrated system may feed back as constraints on the wells in the reservoir simulation models 16. One way that the controller 10 communicates with the other software applications is detailed in the International Publication number WO2004/049216 A1 referenced above.

#In FIG. 1, the coupling controller 10 (a Field Management Tool) communicates with a selection of reservoir simulators 16 and surface network simulators 14 via a communication interface 18. The controller 10 manages the balancing of the reservoirs and surface networks and synchronizes their advancement through time. The controller 10 also applies the global production and injection restraints, and converts the hydrocarbon fluid streams between the different sets of pseudo-components used in the simulation models. In FIG. 1, the integrated surface and subsurface modeling system 12 of FIG. 1 includes a multi-platform reservoir and network coupling controller 10 that is adapted for affecting reservoir field development and optimization by analyzing a pressure interaction between a reservoir 16 and a constrained surface facility network 14 or by predicting a behavior of several reservoir fields which may have different fluid compositions sharing a common surface facility. The controller 10 practices a method for integrated reservoir and surface facility network simulations which includes: communicating between the multi-platform reservoir and network coupling controller 10 and at least one reservoir simulator 16 and between the controller 10 and at least one surface network simulator 14 (hereinafter called the ‘communicating step’). The surface and subsurface modeling system 12 includes a communication interface 18 which is associated with the reservoir simulator 16 and the controller 10 and the surface network simulator 14, the communication interface 18 being adapted for managing a balancing of the reservoir simulator 16 and the surface network simulator 14 and synchronizing the advancement of the reservoir simulator 16 and the surface network simulator 14 through time. The above referenced communicating step includes communicating, by the controller 10, with the reservoir simulator 16 and the surface network simulator 14 via the communication interface 18, the interface 18 enabling the reservoir simulator 16 application and the surface network simulator 14 application to exchange data. When the communication interface 18 is enabled, the controller 10 is adapted to engage in a defined dialog with the reservoir simulator 16 and the surface network simulator 14, the dialog including executive commands, set commands, and query commands. In addition, the communicating step includes coupling the reservoir simulator 16 to the surface network simulator 14. The coupling step includes coupling, by the controller 10, a single reservoir simulator model 16 to the surface network simulator 14 application. When the controller 10 couples the single reservoir simulator model 16 to the surface network simulator 14 application, a tight iteratively lagged coupling scheme is applied, the tight coupling scheme balancing the network simulator application 14 with the reservoir simulator application 16 at each Newton iteration of the reservoir simulator's time step calculation. The coupling step further includes coupling, by the controller 10, two or more reservoir simulator models 16 to the surface network simulator application 14. The two or more reservoir simulator models 16 are subject to common global constraints, and, when the controller 10 couples the two or more reservoir simulator models 16 that are subject to common global constraints to the surface network simulator application 14, a loose coupling scheme is applied wherein, during the loose coupling scheme, the reservoir simulator models 16 are balanced with respect to their global constraints at the start of each synchronization step in the controller 10 and, thereafter, each reservoir simulator model 16 advances independently to a start of a next synchronization step.