365 results about "Reservoir simulation" patented technology

The present invention, in one embodiment, is directed to a method and system for accelerating and improving the history matching of a well bore and/or reservoir simulation model using a neural network. The neural network provides a correlation between the calculated history match error and a selected set of parameters that characterize the well bore and/or the reservoir. The neural network iteratively varies a selection and/or the value of the parameters to provide at least one set of history match parameters having a value that provides a minimum for the calculated history matching error.

The invention relates to a method for predicting the performance of large-scale hydrocarbon-bearing reservoir floods. One embodiment of the invention includes a method for predicting performance of a patterned flooding process in a subterranean hydrocarbon-bearing formation, said formation being penetrated by a plurality of injector wells and producer wells, comprising the steps of: determining flow-based pairs of injector to producer wells [FIG. 4, item 78a] (first well pairs) using a geological model [item 76]; developing a connective pore volume distribution curve for each first well pair item [78b]; selecting at least two first well pairs (selected well pairs) that reflect narrow and wide connective pore volume distributions that correspond to high and lower oil recovery levels; developing a 3-D simulation model for each selected well pair, performing a reservoir simulation for each selected well pair for the corresponding flooding process; and generating prototype performance curves for each selected well pair. An alternate embodiment of the invention includes a method for predicting the performance of large-scale hydrocarbon-bearing reservoir floods where injection well location, production well location, a process parameter, or a well processing rate is modified.

A method of generating a hybrid grid of a heterogeneous formation crossed by one or more geometric discontinuities such as, for example, an underground formation where one or more wells have been drilled, or a fractured formation, by combining structured grids and non-structured grids in order to carry out simulations in accordance with a defined numerical pattern is disclosed. Hybrid gridding is performed by associating a first structured grid (G1) for gridding of the heterogeneous medium considering discontinuities thereof with second structured, radial type grids (G2) for gridding of a zone around each pipe or well, which allows better consideration of constraints linked with flows in the zone. In order to connect the first grid of the medium and the second well grids, non-structured transition grids (G3) are interposed there between. A power diagram technique is used, which is particularly advantageous in that it allows appropriate connection of non-regular structured grids. An application is hydrocarbon reservoir simulation.

Disclosed are methods for simulating pressures and saturations of oil, gas, and water in an oil reservoir with production and injection wells, which include (1) using of new approximating linear algebraic (finite difference) equations that more accurately represent actual pressures by basing the equations on new functional forms: ln(r) or 1/r, (2) solve the set equations using by defining a coarse grid array and a fine grid array nested in the fine grid array, and solving the coarse grid array and using the resulting solution to fix points in the fine grid array before it is solved, and (3) defining and solving a dynamic grid array based upon constant saturation contours.

The invention provides a method for analyzing remaining oil distribution of a fractured-vuggy reservoir, belonging to the fields of numerical reservoir simulation and oil-gas field development. In the method, a complex medium consisting of a cave medium, a crack medium and a pore medium is partitioned into a plurality of space unit blocks in a space field; each block consists of V, F and M units which represent a cave, a crack and a substrate in the block respectively and constitute a V-F-M model; the flow of a multi-phase fluid in the complex medium is described by the motion of a fluid among the units in each block and the motion of a fluid among the units of different blocks; and the flow of the fluid among the units can be considered as infiltration flow, pipe flow or laminar flow between parallel walls, Darcy flow or non-Darcy flow. According to the method, scientific description and accurate numerical simulation of the fractured-vuggy reservoir are realized, and technical foundations are laid for the alignment of the remaining oil distribution position of the fractured-vuggy reservoir with a numerical simulation technology, quantitative determination of the reserves abundance of the reservoir, scientific and reasonable development of oil fields provided with the reservoir and final increase in the recovery ratio.

A hybrid evolutionary algorithm (“HEA”) technique is described for automatically calculating well and drainage locations in a field. The technique includes planning a set of wells on a static reservoir model using an automated well planner tool that designs realistic wells that satisfy drilling and construction constraints. A subset of these locations is then selected based on dynamic flow simulation using a cost function that maximizes recovery or economic benefit. In particular, a large population of candidate targets, drain holes and trajectories is initially created using fast calculation analysis tools of cost and value, and as the workflow proceeds, the population size is reduced in each successive operation, thereby facilitating use of increasingly sophisticated calculation analysis tools for economic valuation of the reservoir while reducing overall time required to obtain the result. In the final operation, only a small number of full reservoir simulations are required for the most promising FDPs.

A method for mapping a fracture network that includes determining a source of at least one seismic event from features in recorded seismic signals exceeding a selected amplitude (“visible seismic event”). The signals are generated by a plurality of seismic receivers disposed proximate a volume of subsurface to be evaluated. The signals are electrical or optical and represent seismic amplitude. A source mechanism of the at least one visible seismic event is determined. A fracture size and orientation are determined from the source mechanism. Seismic events are determined from the signals from features less than the selected amplitude (“invisible seismic events”) using a stacking procedure. A source mechanism for the invisible seismic events is determined by matched filtering. At least one fracture is defined from the invisible seismic events. A fracture network model is generated by combining the fracture determined from the visible seismic event with the fracture determined from the invisible seismic events.

The present invention discloses a multi-year regulating storage reservoir optimal scheduling method considering runoff uncertainty. The method comprises the following steps of: (1) analyzing historical reservoir runoff data; (2) establishing a runoff random simulation model, and generating a reservoir simulation annual runoff sequence; (3) simulating annual inflow runoff sequence classification and performing intra-annual distribution to obtain a three-year inflow runoff process sequence on a month scale; (4) establishing a multi-year regulating storage reservoir optimal scheduling model that considers multiple water demands; and (5) reducing dimension by using an optimization algorithm and optimizing a resolution model so as to obtain an optimal discharging and water supply decision. According to the method provided by the present invention, the scheduling with maximized comprehensive benefits of long-term multi-target operation can be performed on a multi-year regulating storage reservoir by considering runoff uncertainty, so that the method is suitable for promotion in long-term optimal scheduling of the multi-year regulating storage reservoir in China.

The invention is a method for inferring the saturation and pressure change of a reservoir by combining the information from 4D (time-lapse) seismic and time lag data volumes (7) derived from the 4D seismic, well logs (4), and reservoir simulation results (when simulator results are available) and featuring one or more 4D well ties (1) for a quantitative 4D interpretation. The inventive method uses model-based inversion incorporating rock physics (2) at well locations (5), and is statistical-based (6) away from wells. The method thus allows integration (8) of rock physics model and reservoir simulation and honors 4D seismic change.

The present disclosure generally relates to synthetic logging for reservoir stimulation. A synthetic logging method for stimulating a reservoir includes: training a machine learning algorithm using historical or exploratory data; and generating a synthetic elastic property log of the reservoir by supplying the trained machine learning algorithm with data acquired from a production wellbore.

A method for solving a matrix equation AX=B, wherein A represents a block sparse matrix, B represents a right hand side block vector and X represents a solution block vector. In one embodiment, the method includes receiving the block sparse matrix and the right hand side block vector, constructing a reduced transformed block sparse matrix from the block sparse matrix, constructing a reduced transformed residual block vector from the block sparse matrix and the right hand side block vector, and solving for the solution block vector using the reduced transformed block sparse matrix and the reduced transformed residual block vector.

A computer-based system analyzes reservoir simulation results with a rule-based event monitor to trigger appropriate warnings in the event any of a number of applicable reservoir operation conditions is detected as likely to occur. The conditions may be automatically analyzed on multi-dimensional data during successive time steps to detect events indicated as needing attention or analysis and thus to alert reservoir engineers about operating conditions in the reservoir so that the engineers may make appropriate operational or simulation changes. The conditions may also be automatically analyzed in a batch processing mode of a set or subset of available time steps to detect and generate a log of events encountered that are indicated as needing attention or analysis.

A linear solver methodology is applied to reservoir data to solve for large system of equations arising from high-resolution reservoir simulation of giant oil fields with minimal upscaling using either structured grids or unstructured grids. Full geologic complexity and discontinuities at the resolution desired for accurate simulation results may be taken into account. A general unstructured method is provided, so that very complex flow geometry near multi-lateral wells can be modeled.

A method producing full field radial grid (called here Radial-X Grid) for more accurate and efficient reservoir simulation and improving simulation work flow. The Radial-X Grid method produces both aerial and vertical gridding to divide a reservoir structure into simulation grid cells. The aerial gridding is performed by 1) specifying a reservoir boundary (including faults) and well locations; 2) distributing a set of concentric circles around each well location; 3) determining the circle-circle and circle-boundary intersection locations of these circles; 4) forming the aerial grid by selecting circles, arc segments of intersecting circles and radial lines which connect the ends of these arc segments to the corresponding well center; 5) and forming additional grid lines by selecting the connecting lines of two wells if their circles intersect, adding additional radial lines to certain wells, and connecting end points of certain selected arc segments. Thus, the aerial boundary of each individual grid cell is formed from elements selected from the group of arc segment, well radial line, reservoir boundary, connection line of well to well, arc segment end to arc segment end. The vertical gridding is performed by casting the aerial grid vertically downwardly through all the layers defined in the reservoir structure. The Radial-X Grid method is advantageous for petroleum reservoir simulation applications because it is easy to use, runs fast, produces no grid orientation effect, provides efficient use of grid cells, provides precision modeling and provides better reservoir boundary and fault conformance.

An efficient percolation aggregation solver methodology captures media connectivity and continuity to reliably incorporate relevant flow solution trends in subterranean formation models. The approach allows introduction of meaningful physical information that is generally overlooked by state-of-the-art algebraic algorithms in the solution process. Percolation aggregation extends the efficiency and robustness of solution methods used to solve scientific and engineering problems.

The invention discloses a well pattern rebuilding method and device for the water-injection development of an old oil field. The method comprises the steps that various factors for influencing well pattern arrangement are taken into account, and mesh parameter data in geologic modeling and numerical reservoir simulation computed results are stacked and computed to obtain parameter distribution of series of strata; the mesh comprehensive evaluation index of the series of strata is computed, and a comprehensive evaluation index distribution diagram of the series of strata is obtained; well patterns are arranged on the comprehensive evaluation index distribution diagram of the series of strata according to different well pattern types, well positions are adjusted according to the characteristics of the comprehensive evaluation index distribution diagram, and initial well pattern arrangement schemes are obtained; for each initial well pattern arrangement scheme, old wells are searched for around the signal wells, and whether the oil wells are utilized is determined according to well conditions and an injection-production relationship; each well pattern arrangement scheme formed finally is evaluated, and the relatively-optimal well pattern arrangement scheme is selected according to the well pattern control degree and a recovery efficiency index. The well pattern rebuilding method and device for the water-injection development of the old oil field can meet the well pattern arrangement requirements of old oil fields in the secondary development process.