WO2010120806A2

WO2010120806A2 - System, method and apparatus for optimizing management of water for oil and gas operations

Info

Publication number: WO2010120806A2
Application number: PCT/US2010/030925
Authority: WO
Inventors: Richard P. Broderick; Russell Fontaine; Jeffrey A. Anderson; Robert A. Will; Peter Dolph
Original assignee: Schlumberger Canada Limited; Services Petroliers Schlumberger; Schlumberger Holdings Limited; Schlumberger Technology B.V.; Prad Research And Development Limited
Priority date: 2009-04-13
Filing date: 2010-04-13
Publication date: 2010-10-21
Also published as: WO2010120806A3

Abstract

An apparatus for optimizing a water management system for an oilfield operation having an anticipated life comprising computer readable memory containing water inflow data, water outflow data and an economics database; a bus for communication with the memory; a processor in communication with the bus; one or more input devices in communication with the bus; one or more output devices in communication with the bus; a graphical user interface and an analysis toolbox built on a system analysis platform in communication with the bus, the analysis toolbox capable of using data from memory to optimize one or more aspects of the water management for a time segment of the anticipated life of the oilfield. A method for using the apparatus for optimizing water handling for an oilfield operation over a time segment is also provided.

Description

SYSTEM, METHOD AND APPARATUS FOR OPTIMIZING MANAGEMENT OF WATER FOR OIL AND GAS OPERATIONS

BACKGROUND

Field of the Invention

[0001] This invention relates to improved methods and systems for management of water in oil and gas operations. In particular, the invention provides methods, apparatuses and systems for more effectively and efficiently managing water needed for and/or produced by oil and gas operations.

Background

[0002] Water is generally needed for use in oil and gas ("hydrocarbon") exploration and production operations. In addition to the physical needs of the personnel working on site for the field operations, which are often in remote locations, water is often needed for direct use in drilling and producing hydrocarbon wells. As is well known in the art, water may be needed to make drilling or completions fluids or to make cement for setting casing in the wells or for creating cement plugs in the wells. Water may be used to make fluids to stimulate production in a well during acidizing or fracturing operations, such as, but not limited to, the large water volume hydraulic fractures (slick water fracs) currently used for completing shale gas or similar unconventional gas reservoirs. Water may also be needed for enhanced oil recovery (EOR) of hydrocarbons in producing oilfields. (The use of the term "oilfields" is used herein as it is commonly used in the industry to include not only oil production fields but fields that produce natural gas and/or other hydrocarbons as well.) For example, water may be used in waterfiood operations where it is injected below the surface, through injection wells, into a producing reservoir at one or more points to push hydrocarbons towards producing wells. Water may also be needed for cleaning the drilling or completion rig or other site-related purposes.

[0003] But water may impact the hydrocarbon operations in other ways. Operators of oil and gas fields may need to ensure that their operations do not harm potentially sensitive drinking water aquifers. Once a well is in production, there may be formation water produced along with the hydrocarbons and water production may increase significantly during the life of the field. The produced formation water may be saline and may contain other undesirable elements and chemicals. Produced water may be susceptible to being treated and re-used or may require proper disposal. The fluid from an acid or fracturing operation of a well may also flow back to the surface and contain undesirable chemicals and may need to be properly disposed of.

[0004] Satisfying all of the needs of oil and gas operations in widely different venues requires careful analysis and balancing of differing options and technologies. All basins, fields, sites offer a unique set of problems and each operator requires a custom set of solutions. By applying an integrated oilfield water management system, operators will better adapt to forecast water disposal and supply demands, develop new uses for oilfield water, manage oilfield water in an environmentally compliant fashion, and reduce their water management costs- both operating and capital expenditures. Produced water management systems contain many elements which may be applied in different combinations, and which may interact or be dependent upon one another as well and production system. Effective integrated water management should take into account all of the potentially viable combinations from perspectives including operational, economic, regulatory, and client preferences. As such, a component of an integrated management system is an analytical tool which facilitates rapid predictive modeling of many different potential water management scenarios, and which provides decision support diagnostic information for evaluation of both the operational and economic performance of each. The above analyses should take into account uncertainties in each part of the system such as water production forecasting, environmental factors, water management component performance, and costs.

[0005] There an integrated approach to managing water during oil and gas operations may be useful. 2010/030925

SUMMARY

[0006] An objective of the present invention is to provide methods, apparatuses and systems for integrated management and optimization of water involved in oil and gas exploration and production operations, while eliminating or minimizing the impact of the problems and limitations described.

[0007] The present invention includes a method of optimizing water management for an oil and gas operation, which includes providing an adequate water supply for oilfield operations projected to be needed for life of the oilfield, providing adequate produced water treatment for an intended purpose of the produced water, providing an optimized water transportation system to transport the water supply to the necessary facilities, using treated produced water for beneficial uses; and using an optimization tool to optimize system efficiency for the water management system. The present invention may reduce the costs of water supply, treatment and recycling of frac water, support beneficial use of produced water and protection of groundwater resources, and provide for proper water disposal.

[0008] And embodiment of the invention provides a process of optimizing water management for an oilfield including use of an optimization tool to determine an adequate water supply for oilfield operations projected to be needed for a time segment of the life of the oilfield by determining a water inflow anticipated over the time segment, determining one or more water treatment systems for the water inflow to improve the quality of the water inflow so that the treated water is of a quality acceptable to be used for one or more intended purposes at one or more locations, assessing the amount of treated water to be produced by the water treatment systems over the time segment, using the anticipated water inflow for the time segment, optimizing a water transportation system to transport the water inflow to the water treatment systems and optimizing a treated water transport system to transport the treated water to the one or more locations for the treated water's one or more intended purposes, and performing an economic analysis to determine optimization of water handling for the oilfield operation over the time segment. An intended purpose for the treated water may include, for example, disposal in one or more injection wells, discharge to a retaining pond for future re-use in an oilfield operation, such as re-use for well stimulation, completion, workovers or other well operations or use for non- oilfield purposes such as irrigation, creation of a wildlife habitat such as a wetlands area, or for dust control, or the water may be disposed of in a nearby stream or other waterway in an environmentally compliant manner, Examples o fwell stimulation include but are not limited to acidization, hydraulic fracing, which might include hydraulic fracing of conventional wells or hydraulic fracing of gas shales or other unconventional reservoirs.

[0009] The present invention may base a location of one or more injection well on determination of a most favorable injection zone to maximize injection rate for the depth drilled. The invention may determine that to meet the determined anticipated adequate water supply for oilfield operations, additional water should be supplied through one or more monitored water wells or through treatment of water inflow or some combination thereof. The invention may include designing and/or using a pre- treatment system used before treatment system. The water inflow considered by the invention may include water produced from flowback from a well stimulation or other well operations, or formation water co-produced with hydrocarbons or any combination thereof. The invention may design or provide that treated water is augmented with chemical additives for use in well stimulation. The optimization tool of the present invention may design treatment systems which may include pre- treatment systems for water ingflow from one or more sources and may perform water balance analyses and/or economic analyses for the water handling system. Such an economic analysis may include a financial summary of the water handling system and may include a cumulative cash flow/net present value analysis, sensitivity analysis, and/or an uncertainty analysis. The economic analysis may be performed over one time segment or over different time segments.

[0010] One embodiment of the present invention provides a process of optimizing water management for an oilfield including use of an optimization tool to determine an adequate water supply for oilfield operations projected to be needed for a time segment of the life of the oilfield by determining a water inflow anticipated over the time segment, determining one or more water treatment systems for the water inflow to improve the quality of the water inflow so that the treated water is of a quality acceptable to be used for one or more intended purposes at one or more locations, assessing the amount of treated water to be produced by the water treatment systems over the time segment, using the anticipated water inflow for the time segment, optimizing a water transportation system to transport the water inflow to the water treatment systems and optimizing a treated water transport system to transport the treated water to the one or more locations for the treated water's one or more intended purposes, and performing an economic analysis to determine optimization of water handling for the oilfield operation over the time segment, wherein additional water for oilfield operations is supplied through one or more monitored water wells, one intended purpose for the treated water is disposal in one or more injection wells, the location of the one or more injection wells based on determining a most favorable injection zone to maximize injection rate for the depth drilled, and the optimization tool evaluates produced water, distribution and treatment of the produced water, and disposition of the treated water and provides a water balance summary and a finance summary as part of the economic analysis. One embodiment of the present invention provides a system of optimized water management for an oil and gas operation including projection of an adequate water supply for oilfield operations projected to be needed for life of the oilfield; design of water inflow treatment facilities sufficient for to treat the water inflow produced from one or more water inflow sources, to a quality sufficient for one or more intended purposes of the treated water at one or more locations, an optimized water transportation system to transport the water supply to the needed operations, the water inflow from the water inflow sources to treatment facilities and the treated water to the one or more locations for the treated water's one or more intended purposes, and an optimization tool to optimize system efficiency for the water management system using a water balance summary and a finance summary. The optimization tool may evaluate the produced water, distribution and treatment of the water inflow, and disposition of the treated water for the one or more intended purposes of the treated water. The optimization tool may evaluate produced water, distribution and treatment of the produced water, and disposition of the treated water cost analysis, and provide a water balance and cost summary while taking into account takes into account uncertainty in cost and performance of system components. [0012] An embodiment of the present invention provides a process of optimizing water management for an oil and gas operation including providing adequate water supply for oilfield operations projected to be needed for life of the oilfield or a time segment thereof, providing an optimized water transportation system to transport the water supply to the needed operations, the produced water to disposal in one or more injection wells, either with or without treatment beforehand, and wherein the one or more injection wells are pre-existing wells the injectivity of which has been enhanced using the optimization tool.

[0013] An embodiment of the present invention includes a process and/or a system of providing adequate water supply for oilfield operations projected to be needed for life of the oilfield, providing an optimized water transportation system to transport the water supply to the needed operations, the produced water to disposal in one or more injection wells, and wherein the one or more injection wells is selected using injection well economic optimization.

[0014] An embodiment of the present invention provides an apparatus for optimizing a water management system for an oilfield operation which includes an optimization tool which has a first module for evaluating water inflow over a time segment in the life of the oilfield, a second module for optimizing distribution of water for the oilfield, a third module for optimizing treatment of the water inflow for one or more intended purposes at one or more locations, a fourth module for optimizing water outflow, taking into account water needs of the oilfield over the time segment, a fifth module for performing a water balance summary, and a sixth module for proving a financial analysis. The optimization tool may use the water balance summary and the sixth modiule to perform optimization analyses under various scenarios to determine an optimum configuration for water management in the oilfield over the time segment. The first module may analyze water inflow from water produced from one or more hydrocarbon wells and analyze water inflow from water produced from one or more well stimulation operations.

[0015] One embodiment of the present invention includes an apparatus for optimizing a water management system for an oilfield operation having an anticipated life which includes a computer readable memory containing water inflow data, water outflow data and an economics database, a bus for communication with the memory, a processor in communication with the bus; one or more input devices in communication with the bus, one or more output devices in communication with the bus, a graphical user interface and an analysis toolbox built on a system analysis platform in communication with the bus, the analysis toolbox capable of using data from memory to optimize one or more aspects of the water management for a time segment of the anticipated life of the oilfield. The analysis toolbox may be in communication with supplemental software and may be capable of initiating performance of supplemental analyses by the supplemental software using data provided by the analysis toolbox. The supplemental software may be in communication with the bus to provide supplemental water optimization analyses through that communication avenue. The time segment is the anticipated life of the oilfield (that is, the remaining life of the oilfield, the full life of the oilfield or any segment thereof. The water inflow data may include a water inflow database and a collection of water inflow chemistry. The water outflow data may include a water outflow database, a collection of water outflow chemistry, a disposed water database and a reused water database. Another embodiment of the invention includes a system of optimized water management for a segment of a life of an oilfield including a first module for modeling one or more sources of water inflow, a second module for modeling a distribution system for distributing water in the oilfield, a third module for modeling a treatment system for the water inflow to create a water outflow wherein the water quality of the water outflow is better than the water inflow, a fourth module to model disposition of the water outflow to one or more locations for one or more respective purposes, a water balance module to provide a water balance analysis of the water inflow and water outflow based on data from the first module, second module, third module and forth module, and an economics module to provide economics analysis of the water management system over the time segment. The system may include a fifth module to model one or more water sources for the oilfield. The system may also include supplemental software to use data from one or more of the modules and perform supplemental analyses. [0017] Other objects, features and advantages of the present invention will become apparent to those of skill in art by reference to the figures, the description that follows and the claims.

BRIEF DESCRIPTION OF DRAWINGS

[0018] FIG. 1 is a depiction of an overview of an integrated oilfield water management process of one embodiment of the present invention.

[0019] FIG. 2 depicts additional detail for water pre-treatment and treatment.

[0020] FIG. 3 depicts additional detail for water disposal.

[0021] FIG. 4 depicts additional detail for water supply 60.

[0022] FIG. 5 depicts a screenshot for PIPESIM, a commercially available software program which may be used to model the conveyance piping and pumping which ties the water operation together in one embodiment of the present invention.

[0023] FIG. 6 depicts a representation of an optimization tool in accordance with one embodiment of the present invention.

[0024] FIG. 7 depicts an injection well economic optimization system in accordance with one embodiment of the present invention.

[0025] FIG. 8 depicts a representation of one embodiment of an injection well economic optimization system in accordance with one embodiment of the present invention.

[0026] FIGURES 9-15 depict examples of types of analyses which may be performed with one embodiment of an optimization tool in accordance with one embodiment of the present invention.

[0027] FIG. 16 depicts a block diagram of an optimization tool in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION

[0028] In the following detailed description of a preferred embodiment and other embodiments of the invention, reference is made to the accompanying drawings. It is to be understood that those of skill in the art will readily see other embodiments and changes may be made without departing from the scope of the invention.

[0029] FIG. 1 is a depiction of an overview of an integrated process of one embodiment of the present invention. Fluids 2 from an underground reservoir 3 are produced to the surface through a production well 4. The produced fluids 4 may include oil, gas, condensate or other hydrocarbons, as well as water. The hydrocarbons in the fluids 2 are separated from the water in the fluids 2 using initial separation equipment 6. The initial separation equipment 6 may include but is not limited to heaters, separators and dehydrators, Water pretreatment and treatment processes and systems 10 may include cleaning of water such as the water isolated from the produced fluids 2 for disposal or for re-use of the water. Water may be reused, for example, for well stimulation or through frac tanks 30 to be mixed with chemical additives to be used for hydraulic fracturing 12. The chemical additives may allow water even with high total dissolved solids (TDS) water to be used in hydraulic fracturing and re-use/re-cycle the water for other well stimulations or for completions, well cementing, workovers or enhanced recovery, Water which has been appropriately treated may be used for environmentally compliant consumptive non-oilfield use, such as irrigation 40 such as managed or drip irrigation to re-saturate the vadose zone for enhanced evapotranspiration to grow crops, creating wetlands, dust control, or discharge to nearby streams 65 or other waterways.

[0030] Pre-treatment may include removal of suspended solids and disinfecting the water. For treatment, preferably all available options are evaluated for a site-specific solution, considering both the water used (also called "feed water") and intended final use. These pre-treatment and treatment options (which may be used singly or in various combinations) may include:

• Filtration

• Disinfection

• Adsorption

• Chemical reaction

• Chemical addition

• Ionic exchange

• Membrane filtration

• Thermal distillation [0031] In an embodiment of the present invention, an optimization tool (not depicted in FIG. 1) integrates petroleum and hydrogeological data for water disposal to optimize the water process for hydrocarbon production locations, including but not limited to optimizing injection well 20 locations, based on selecting a most favorable injection zone and maximizing the injection rate for the depth drilled to reduce disposal costs and increase project profitability. The optimization tool can be used in accordance with the present invention to evaluate existing wells and make recommendations to enhance their injectivitity.

[0032] Monitoring and protection of usable groundwater supplies may be accomplished with use of underground sensors 50 such as Van Essen DIVERS, monitoring systems such as WESTBAY, and/or hydrogeologic software such as WATERLOO software products, including but not limited to Visual MODFLOW or HydroGeoAnalyzer. Design and installation of efficient and cost effective water supply wells 60 also may use products and technology which may include underground sensors such as Van Essen, monitoring systems such as Westbay, and WATERLOO software products, including but not limited to Visual MODFLOW or HydroGeoAnalyzer. Such technology is also applicable to aquifer storage and recharge projects. Tying all of these processes together is the optimization tool (not depicted in FIG. 1), which may facilitate evaluation of operational water balance including such factors as water supply, handling of produced water, water uses, and final disposal with project economics under conditions of uncertainty to quantity existing costs and reduce future water handling costs. The optimization tool may in accordance with one or more embodiments of the present invention provide integrated modeling and decision support functions including;

• Design for both short term peak loads and long term base loads.

• Evaluation of safe excess capacity without overbuilding.

• Evaluation of uncertainty in both water balance and cost components.

• Evaluation of numerous "what if scenarios with regard to possible variations in supply, regulatory environment, operational constraints, and cost factors.

• Evaluation of where to expend data gathering resources to effectively reduce key uncertainties.

[0033] The optimization tool can optimize water use, re-use and disposal over a selected time segment, which might be the life of the field, but might be a shorter time segment. [0034] FIG. 2 depicts additional detail for water pre-treatment and treatment 10, in an embodiment of the present invention. Embodiments of the present invention consider specific treatment requirements and the conditions on site. Feed water quality, discharge water quality, regulatory issues, water balance inflows and outflows, modular vs. centralized units, required capital costs, as well as operational and maintenance costs, are important aspects for optimizing water pre-treatment (if needed) and treatment.

[0035] FIG. 3 depicts additional detail for disposal of produced water, such as through an injection well 20, in an embodiment of the present invention. Water disposal may include solutions such as impoundments and misters, injection wells such as the injection well depicted in FIG. 3, managed or drip irrigation (typically with some form of pre-treatment or treatment), treatment and discharge or integration of multiple solutions. Optimizing water disposal in accordance with embodiments of the present invention may include use of injection well economic optimization, up- front characterization and engineering design.

[0036] FIG. 4 depicts additional detail for water supply and use, in an embodiment of the present invention. Freshwater may be supplied for stimulation and fracture work and operations and maintenance. Freshwater may be supplied from one or more water supply wells 60. The freshwater may be supplied all or in part from re-use of available produced water 22 from existing wells, after any necessary pre-treatment, treatment and/or chemical enhancement, (as depicted in more detail in FIG. 1). Freshwater may be stored on the surface as surface water such as in ponds 24 (if environmentally compliant), which may also collect rainwater or runoff, or may be stored underground (not depicted). Properly treated water may be supplied for non-oilfield purposes such as crop irrigation 40 or may be discharged to a nearby stream 65. FIG. 4 depicts use of fresh water for a hydraulic fracture 12, fresh water storage being supplied from surface water 24. FIG. 4 also depicts a water supply well 60. a monitoring well 50 sending signals offsite and a managed irrigation of crops 40.

[0037] FIG. 5 depicts a screenshot 100 for PIPESIM, a commercially available software program generally used for oilfield applications, but which may be used to model the conveyance piping and pumping which ties a water operation together and which may be used in one or more embodiments of the present invention. The PIPESIM screen shot 100 of FIG. 5 depicts flow of excess produced water from a producing well through a series of pipelines to subsurface water injection wells (though of course, in many situations, there may be several producing wells and one injection well). The PIPESIM screenshot 100 depicts a producing well and injection wells. Proper planning for and provision of properly sized equipment such as properly sized pipes and correct pump types eliminate bottlenecks and reduce lost time due to damaged equipment. For example, water volumes may collapse pipe if there has not been proper planning for freezing conditions. Proper preventive measures and monitoring for corrosion or abrasion may be needed. In addition, planning for operations which will be needed through the life of the field can reduce lost time as operational needs change, for example, when completions, workovers or well stimulation are needed, especially at short notice. FIG. 7 depicts a method for using the optimization tool 200 in accordance with an embodiment of the present invention. The optimization tool may include one or more elements, such as: (1) an economic database 202 (which might take into account for one or more geographic areas of interest costs of drilling one or more injection wells, costs of installing equipment for one or more injection wells and operating one or more injection wells); (2) a chemical database including a collection of baseline reservoir water quality and disposal water chemical data 204 in potential injection target zones potential injection target zones; and (3) an injection database 206 for geologic formations of interest including geology (such as geologic tops from geophysical logs); aquifer, reservoir and fluid properties. The optimization tool would use the data in the elements such as the economic database, the injection database and the chemical database to derive 208 geologic interpretations of key target injection zones the area of interest and structure contour and/or isopach maps (e.g. on regional basis). The optimization tool may expand interpretations to other areas, such as geochemistry, with a geochemistry database properly configured to accept such data. The optimization tool can analyze 210 historical injection data from the injection database to create a series of retrievable calculated fields such as for example, current volumes injected by geologic formation, projected ultimate life of well and total barrels of produced water, capital and operating costs, and cost per barrel for produced water for disposal. The retrievable calculated fields can be stored in and retrieved from the injection database. Based on the geologic interpretations of key target injection zones and the retrievable calculated fields, the optimization tool may create 212 a list of key factors for successful injection projects. The optimization tool may include a derived key data database 214 sufficient to store and retrieve key data on specific aquifers of interest.. (The injection database, the economic database, the chemical database and the key data database may be separate databases, but one of more of the databases may alternatively be combined into a single combined database.) The optimization tool would include or be used with software for facilitating data retrieval and analysis for one or more of the databases included with that embodiment of the present invention. The key data database may be accessible over the web and such access may or may not be limited to read-only access. The optimization tool would preferably include a web-based GUI front end 216 to display data. The optimization tool may use one or more of all of these elements to identify optimum target zones for water injection and selection of optimum areas for water injection. The optimization tool may also include superimposed key map coverages 218, which may be GIS-based and may include state and county boundaries, township-range-section, cities and roads, and topography. The superimposed key map coverages may be used by the optimization tool to create a matrix of permitting requirements 220 for jurisdictions of interest. The optimization tool may identify optimum target zones 222 and select optimum areas for injection 224. FIG. 6 depicts a representation of the optimization tool 101 in accordance with one embodiment of the present invention, including details at various points in the process. The optimization tool facilitates forward modeling of complex systems of interacting system components including produced water from production and/or well fracture work (or other stimulation), distribution and treatment (including any pre-treatment) of the produced water, and the disposition of the water, which may include injection, ponds, and/or irrigation. The optimization tool may provide a water balance summary. The optimization tool may provide a finance summary, which may include analyses such as a cumulative cash flow/NPV analysis and/or a sensitivity analysis. The optimization tool is best developed in a programming environment which provides both linear system optimization and Monte-Carlo simulation. The optimization tool may be built on a system analysis platform which allows interactive combinations of connected processes of complex water management operational scenarios and associated costs through the life of the asset. The best system analysis platform for the present invention is currently believed to be GoldSim, a commercially available software program. The system analysis platform may exchange data with and initiate execution of supplemental software for providing specialized enhanced analyses. The specialized enhanced analyses may include but are not limited to water treatment analyses, network pipe-flow analyses and/or additional economic analyses. Probabilistic modeling techniques may be employed to explore the impact of uncertainty and to quantify risk with regard to both water budget and overall water management costs. The result of the analysis may be one or more water management strategies which are optimized on either operational or cost efficiency or both.

[0040] In FIG. 6, the optimization tool 101 is depicted as including water inflow modules such as a production module 102 and a well frac module 106. A stochastic production function 104 created by the optimization tool is depicted. Output from the water inflow modules 102, 106 is used by a distribution module 110, Pipeline analysis software such as PIPESIM may be used with the distribution module 110. Output from the distribution module 110 is used as input to the treatment module 112. Output from the treatment module is used as input to water output modules, such as an injection module 120, ponds module 122, and irrigation module 124, and as input to a water balance summary module 130. The optimization tool may use the water balance summary module 130 to create a water balance summary 132. Information from the water output modules and the water balance summary module 130 is used with a finance summary module 140 to perform economic analyses such as a sensitivity analysis 142 and cumulative case flow/net present value ("NPV") analysis 144.

[0041] One or more of the following needs may be addressed by the optimization tool in accordance with one or more embodiments of the present invention: (1) a need to consider operational, regulatory, and economic factors; (2) a need to design for both short term peak loads and long term base loads; (3) a need to include safe excess capacity but avoid overbuilding; (4) a need to comprehend uncertainty in both water balance and cost components; (5) a need to be able to easily evaluate numerous "what if scenarios with regard to possible variations in supply, regulatory environment, operational constraints, and cost factors; or (6) a need to understand where to expend data gathering resources to effectively reduce key uncertainties.

[0042] FIG. 8 depicts a decision analysis flowchart for the optimization tool in accordance with one embodiment of the present invention. Water balance analysis 132 and financial module 140 may be used to prepare economic analyses 141, such as evaluation unit costs, cash flows as well as sensitivity analysis and uncertainty analysis.

[0043] FIGURES. 9-15 depict different analyses that might be performed by one embodiment of the optimization tool. FIG. 9 depicts a water production decline curve analysis, FIG. 10 depicts a water balance sensitivity analysis, FIG. 11 depicts a water balance summary; FIG. 12 depicts a water production uncertainty analysis: for an option of an immediate build-out; FIG.13 depicts a water balance uncertainty; FIG. 14 depicts a cumulative distribution function for a water disposal cost in unit cost $/BBL; and FIG. 15 depicts a water production uncertainty analysis for a phased build-out (as opposed to the option of an immediate build-out depicted in FIG. 12). The analyses depicted in FIGURES 9-15 indicate that for the example depicted therein, a phased build-out would require one fewer injection well over the life of the field, making a phased build-out a preferable alternative. The preferable alternative may then be implemented in the field.

[0044] FIG. 16 is a block diagram of the optimization tool in an embodiment of the present invention. Computer readable memory 300 contains water inflow data 302, water outflow data 310 and an economics database 318. Water inflow data 302 may be in the form of a water inflow database 303 and a collection of water inflow chemistry 304. Water outflow data 310 may be in the form of a water outflow database 311, a collection of water outflow chemistry 312, a disposed water database 313 and a reused water database 312. Memory would communicate through a bus 320, the bus 320 also being used for communication with a processor 322, one or more input devices 324 (such as but not limited to a mouse, keyboard, or speech recognition tools), one or more output devices 326, a GUI 330, an analysis toolbox 332, and supplemental software 340. The GUI 330 and the analysis toolbox 332 are preferably built on a system analysis platform 334, such as GOLDSIM. The supplemental software 340 may be initiated by the analysis toolbox 332 and may exchange data directly with the analysis toolbox 332.

[0045] Computer readable program code to perform embodiments of the invention may be stored on a computer readable medium such as a compact disc (CD), a diskette, a tape, physical memory, or any other physical computer readable storage medium that includes functionality to store computer readable program code to perform embodiments of the invention. In one embodiment of the invention the computer readable program code, when executed by a processor(s), is configured to perform embodiments of the invention.

[0046] Although the foregoing is provided for purposes of illustrating, explaining and describing certain embodiments of the invention in particular detail, modifications and adaptations to the described methods, systems and other embodiments will be apparent to those skilled in the art and may be made without departing from the scope or spirit of the invention.

[0047] While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.

Claims

CLAIMSWhat is claimed is:

1. A method of optimizing water management for an oilfield comprising: a. using an optimization tool, determining an adequate water supply for oilfield operations projected to be needed for a time segment of the life of the oilfield; b. determining a water inflow anticipated over the time segment; c. determining one or more water treatment systems for the water inflow to improve the quality of the water inflow so that the treated water is of a quality acceptable to be used for one or more intended purposes at one or more locations; d. assessing the amount of treated water to be produced by the water treatment systems over the time segment; e. using the anticipated water inflow for the time segment, optimizing a water transportation system to transport the water inflow to the water treatment systems and optimizing a treated water transport system to transport the treated water to the one or more locations for the treated water's one or more intended purposes; and f. performing an economic analysis to determine optimization of water handling for the oilfield operation over the time segment.

2. The method as in claim 1 wherein one intended purpose for the treated water is disposal in one or more injection wells.

3. The method as in claim 2 wherein location of one or more injection well is based on determining a most favorable injection zone to maximize injection rate for the depth drilled.

4. The method as in claim 1 wherein, to meet the determined anticipated adequate water supply for oilfield operations, additional water is supplied through one or more monitored water wells.

5. The method as in claim 1 wherein, to meet the determined anticipated adequate water supply for oilfield operations, water is supplied through treatment of water inflow.

6. The method as in claim 5 wherein the one or more water treatment systems includes a pre-treatment system used before treatment system.

7. The method as in claim 5 wherein the water inflow includes water produced from flowback from a well stimulation.

8. The method as in claim 5 wherein the water inflow includes formation water co-produced with hydrocarbons.

9. The method as in claim 5 wherein treated water is augmented with chemical additives for use in well stimulation.

10. The method as in claim 1 wherein one intended purpose for the treated water is for use in well stimulation.

11. The method as in claim 10 wherein the well stimulation is a hydraulic fracture operation.

12. The method as in claim 11 wherein the hydraulic fracture operation is a hydraulic fracture operation for a gas shale.

13. The method as in claim 10 wherein the well stimulation is an acidization operation.

14. The method as in claim 1 wherein one intended purpose for the treated water is for use in a well completion operation.

15. The method as in claim 1 wherein one intended purpose for the treated water is for use in a workover operation on a well.

16. The method as in claim 1 wherein the water inflow includes produced water and optimization tool performs an analysis of the produced water and performs a water balance analysis.

17. The method as in claim 16 wherein the produced water analyzed by the optimization tool is formation water co-produced with hydrocarbons.

18. The method as in claim 16 wherein the produced water analyzed by the optimization tool is water flowed back from well stimulation operations.

19. The method as in claim 16 wherein the optimization tool analyzed pre-treatment of the produced water.

20. The method as in claim 16 wherein one intended purpose of the treated water includes disposal by injection through one or more monitored injection wells.

21. The method as in claim 16 wherein one intended purpose of the treated water includes discharge to a retaining pond for future re-use in an oilfield operation.

22. The method as in claim 16 wherein one intended purpose of the treated water includes irrigation of crops.

23. The method as in claim 15 wherein the economic analysis includes a cumulative cash flow/net present value analysis.

24. The method as in claim 15 wherein the economic analysis includes a sensitivity analysis.

25. The method as in claim 1 wherein one intended purpose for the treated water is for dust control.

26. The method as in claim 1 wherein one intended purpose for the treated water is to provide water for habitats for wildlife.

27. The method as in claim 1 wherein one intended purpose for the treated water is to provide wetlands.

28. The method as in claim 1 wherein: a. additional water for oilfield operations is supplied through one or more monitored water wells; b. one intended purpose for the treated water is disposal in one or more injection wells, the location of the one or more injection wells based on determining a most favorable injection zone to maximize injection rate for the depth drilled; and c. the optimization tool evaluates produced water, distribution and treatment of the produced water, and disposition of the treated water and provides a water balance summary and a finance summary as part of the economic analysis.

29. A system of optimized water management for an oil and gas operation comprising: a. determination of an adequate water supply for oilfield operations projected to be needed for a time segment of the life of the oilfield; b. design of water inflow treatment facilities sufficient for to treat the water inflow, produced from one or more water inflow sources, to a quality sufficient for one or more intended purposes of the treated water at one or more locations; c. provision of an optimized water transportation system to transport the water supply to the needed operations, the water inflow from the water inflow sources to treatment facilities and the treated water to the one or more locations for the treated water's one or more intended purposes; and d. an optimization tool to optimize system efficiency for the water management system using a water balance summary and a finance summary, the optimization tool evaluating the water inflow, distribution and treatment of the water inflow, and disposition of the treated water for the one or more intended purposes of the treated water.

30. A method of optimizing water management for an oil and gas operation comprising: a. providing adequate water supply for oilfield operations projected to be needed for life of the oilfield; b. providing an optimized water transportation system to transport the water supply to the needed operations, the produced water to disposal in one or more injection wells; and c. wherein the one or more injection wells are pre-existing wells the injectivity of which has been enhanced using the optimization tool.

31. A method of optimizing water management for an oil and gas operation comprising: a. providing adequate water supply for oilfield operations projected to be needed for life of the oilfield; b. providing an optimized water transportation system to transport the water supply to the needed operations, the produced water to disposal in one or more injection wells; and c. wherein the one or more injection wells is selected using injection well economic optimization.

32. An apparatus for optimizing a water management system for an oilfield operation comprising: a. an optimization tool comprising: i. a first component for evaluating water inflow over a time segment in the life of the oilfield; ii. a second component for optimizing distribution of water for the oilfield, iii. a third component for optimizing treatment of the water inflow for one or more intended purposes at one or more locations; iv. a fourth component for optimizing water outflow, taking into account water needs of the oilfield over the time segment; v. a fifth component for performing a water balance summary; and vi. a sixth component for proving a financial analysis; and b. the optimization tool using the water balance summary and the sixth component to perform optimization analyses under various scenarios to determine and optimum configuration for water management in the oilfield over the time segment.

33. The apparatus of claim 32 wherein the first component further comprises a module for analyzing water inflow from water produced from one or more hydrocarbon wells and a module for analyzing water inflow from water produced from one or more well stimulation operations.

34. The apparatus of claim 32 wherein the optimization tool evaluates produced water, distribution and treatment of the produced water, and disposition of the treated water cost analysis, and provides a water balance and cost summary while taking into account takes into account uncertainty in cost and performance of system components.

35. An apparatus for optimizing a water management system for an oilfield operation having an anticipated life comprising: a. Computer readable memory containing water inflow data, water outflow data and an economics database; b. A bus for communication with the memory; c. A processor in communication with the bus; d. One or more input devices in communication with the bus; e. One or more output devices in communication with the bus; f. A graphical user interface and an analysis toolbox built on a system analysis platform in communication with the bus, the analysis toolbox capable of using data from memory to optimize one or more aspects of the water management for a time segment of the anticipated life of the oilfield.

36. The apparatus of claim 35 wherein the analysis toolbox is in communication with supplemental software and the analysis toolbox is capable of initiating performance of supplemental analyses by the supplemental software using data provided by the analysis toolbox.

37. The apparatus of claim 35 further comprising supplemental software in communication with the bus to provide supplemental water optimization analyses.

38. The apparatus of claim 35 wherein the time segment is the anticipated life of the field.

39. The apparatus of claim 35 wherein the water inflow data further comprises a water inflow database and a collection of water inflow chemistry.

40. The apparatus of claim 35 wherein the water outflow data further comprises a water outflow database, a collection of water outflow chemistry, a disposed water database and a reused water database.

41. A system of optimized water management system for a segment of a life of an oilfield comprising: a. a first module for modeling one or more sources of water inflow, b. a second module for modeling a distribution system for distributing water in the oilfield; c. a third module for modeling a treatment system for the water inflow to create a water outflow wherein the water quality of the water outflow is better than the water inflow; d. a fourth module to model disposition of the water outflow to one or more locations for one or more respective purposes; e. a water balance module to provide a water balance analysis of the water inflow and water outflow based on the models from the first module, second module, third module and forth module, and f. an economics module to provide economics analysis of the water management system over the time segment.

42. The system as in claim 41 further comprising a fifth module to model one or more water sources for the oilfield.

43. The system as in claim 41 further comprising supplemental software to use data from one or more of the modules and perform supplemental analyses.