Browsing by Subject "Interwell connectivity"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
Item Advances in the development and application of a capacitance-resistance model(2013-05) Laochamroonvorap, Rapheephan; Lake, Larry W.Much effort of reservoir engineers is devoted to the time-consuming process of history matching in a simulator to understand the reservoir complexity. Its accuracy is debatable because only a few inputs are known. Several analytical tools have been developed to investigate reservoir heterogeneity. The reciprocal productivity index (RPI) is a tool to measure the pressure support observed at a producer. The log (water-oil ratio or WOR) plot can be used to indicate the presence of a channel. A capacitance-resistance model (CRM) is a simple tool to estimate the connectivity between a producer-injector pair from the production/injection and pressure data. Generally field operators implement an improved recovery plan such as water-alternating-gas (WAG) flood to improve displacement efficiency. However, the existence of heterogeneity compromises its performance. The first objective of this study is to improve the assessment of tertiary flood performance by integrating the CRM with other analytical tools. The integrated method was applied to a miscible flood field in West Texas. The results suggest strong interwell connectivity found more frequently in the NE-SW direction and the different preferential flow paths of injected CO2 and water. Overall, the results provide insights into the current flood status. The operating conditions of a producer dynamically change because of well/field constraints. These changes can induce significant interference in other wells, which cannot be captured by CRM. The second objective of this study is to develop a capacitance-resistance model with producer-producer interaction (CRMP-P). The CRMP-P, derived from the continuity and Darcy’s equations, accounts for producer-producer interactions. The CRMP-P was applied to data from three different reservoir models. The results suggest that the CRMP-P could fit the data with higher precision than CRM. Consequently, the CRMP-P estimates of reservoir properties are more accurate. Moreover, the estimated transmissibility between producers is in agreement with the reservoir models. The CRMP-P was also applied to Omani field data. The transmissibility results are consistent with previous study and the drilling information. The more accurate information on producer-producer interactions and reservoir properties can assist in history-matching, locating infill wells, and reservoir management planning.Item An electric circuit network model for fluid flow in oil reservoir(2010-12) Munira, Sirajum; Flake, Robert H.; Bostick, Francis X.Interwell connectivity is a very important piece of the puzzle for petroleum engineers. To optimize the injection well flow for increasing the production rate, interwell connectivity is a very important parameter. To build a model that works with better precision and with less effort has always been desired by reservoir engineers. In this study we developed an electric circuit network model (referred as the admittance or ymodel) for calculating the admittance parameters to predict branch flow rates (injectorproducer well pair) of oil reservoirs with precision. The y-model is very simple and efficient model that can predict branch flow very efficiently. Injection and production flow rates are the key data used in this model, which also happens to be the most abundant data for oil reservoirs. Injector well bottom-hole pressure data can also be used in this model if available. The governing equation of the electric circuit analogy of well to well flow rates in the oil reservoir is based on Ohm’s law for admittance. A mathematical procedure is also being developed for this circuit network model which solves a series of equations and finds unique solutions for the admittances and branch flows. These results can further be used for predicting the production flow rate for individual producer well. The model shows very good agreement with the exploration data of real oil reservoir.Item Interwell Connectivity Evaluation from Wellrate Fluctuations: A Waterflooding Managment Tool(2010-07-14) Kaviani, DanialUsing injection and production data, we can evaluate the connectivity between injector and producer well pairs to characterize their interwell regions and provide a tool for waterflood management. The capacitance model (CM) has been suggested as a phenomenological method to analyze the injection and production data for these purposes. Early studies involving reservoir simulation have shown CM to be a valuable tool but also have revealed several shortcomings. Many of these deficiencies have become more transparent in analyzing field data. This work consists of two parts: in the first part, we investigate some of the shortcomings of the CM and attempt to overcome them by modifying the algorithms. In the second part, we relate the problem of interwell connectivity to the rigorous concept of Multiwell Productivity Index (MPI) and provide a semi analytical approach. We have developed two modifications on the CM: the segmented CM that can be used where bottomhole pressures (BHP) are unknown and may change during the analysis interval, and the compensated CM that overcomes the requirement to rerun the model after adding a new producer or shutting in an existing producer. If both BHP changes and shut-in periods occur, the segmented and compensated CMs can be used simultaneously to construct a single model for a period of data. We show several hypothetical cases and a field case where these modifications generate a more reliable evaluation of interwell connectivity and increase the R2 of the model up to 15%. On the other hand, the MPI-based approach can predict the reservoir performance analytically for homogeneous cases under specific conditions. In the heterogeneous cases, this approach provides a robust connectivity parameter, which solely represents the reservoir heterogeneity and possible anisotropy and hence allows improved information exchange with the geologist. In addition, this connectivity parameter is insensitive to possible variations of skin factor and changes in number of wells. A further advantage of the new method is the flexibility to incorporate additional information, such as injector BHP, into the analysis process. We applied this approach on several hypothetical cases and observed excellent evaluation of both reservoir performance and connectivity.