Method for operating an oil and / or gas production facility

Abstract

The invention relates to a method for operating a given facility (10) of oil and / or gas production, the given facility comprising at least one well (12), the method comprising the following steps: - producing, for each well (12), a respective number of volumes of oil and / or gas during a given period, and - calculating, for each well (12), a marginal carbon intensity associated with the last volume produced by said well (12) or said facility (10) or a given sub-group of wells of the facility (10).

Description

[0001] Method for operating an oil and / or gas production facility

[0002] The present invention concerns a method for operating a given facility of oil and / or gas production, the given facility comprising at least one well.

[0003] Oil and / or gas extraction requires energy supply and is responsible for emissions.

[0004] The related emissions linked to energy supply and the extraction are, for example, considered in terms of equivalent CO2 emissions.

[0005] Reducing emissions and / or energy consumption is a key issue nowadays.

[0006] However, the production of oil and / or gas is a necessity in today’s world, such that emissions linked to said activity may be hard to reduce.

[0007] One aim of the invention is thus to offer a method for operating a facility of oil and / or gas production allowing to reduce the emissions impact of the facility. To that end, the invention relates to a method of the aforementioned type, wherein the method comprises the following steps:

[0008] - producing, for each well, a respective number of volumes of oil and / or gas during a given period, and

[0009] - calculating, for each well, a marginal carbon intensity associated with the last volume produced by said well or said facility or a given sub-group of wells of the facility.

[0010] The method allows identifying the well for which the production of the last volume has a high marginal emission.

[0011] According to specific embodiments of the invention, the method also has one or more of the following features, considered alone or according to any technically possible combination(s):

[0012] - the method comprises calculating, for each well, the carbon intensity associated with each volume of the volumes produced by said well,

[0013] - the method comprises calculating a marginal carbon intensity linked to activation associated with said volume based on rate, said calculating comprising defining a respective activation model for each well, the respective activation model comprising a first model of the variation of the production of said well depending on the energy supplied for the activation of the well and a second model of the variation of the emissions associated with the energy needed to supply the activation depending on the activation, the marginal carbon intensity associated with one volume produced by said well comprising the marginal carbon intensity linked to activation associated with said volume,

[0014] - the method comprises determining for each well or for all wells of the facility, from the respective activation model, the emissions associated with the activation of the well or wells depending on the production, - the method comprises calculating a marginal carbon intensity linked to activation associated with said volume based on pressure, the marginal carbon intensity linked to activation associated with a volume being equal to the maximum between the marginal carbon intensity linked to activation base on rate and the marginal carbon intensity linked to activation based on the pressure,

[0015] - the method comprises calculating a marginal carbon intensity linked to pressure support associated with said volume based on rate, said calculating comprising defining a respective pressure support model for each well, the respective pressure support model comprising a first model of the energy supplied for pressure support depending on the production of the well and a second model of the variation of the emissions associated with the energy supplied for pressure support depending on the energy supplied for pressure support, the marginal carbon intensity associated with a volume produced by said well comprising the marginal carbon intensity linked to the pressure support associated with said volume,

[0016] - the method comprises determining for each well or for all wells of the facility, from the respective pressure support model, the emissions associated with the pressure support of the well or wells depending on the production,

[0017] - the method comprises calculating a marginal carbon intensity linked to pressure support associated with said volume based on pressure, the marginal carbon intensity linked to pressure support associated with a volume being equal to the maximum between the marginal carbon intensity linked to pressure support based on rate and the marginal carbon intensity linked to pressure support based on the pressur,

[0018] - the method comprises defining a respective flaring or venting model for each well, the respective flaring or venting model comprising a model of the quantity of gas produced depending on the production, the marginal carbon intensity associated with a volume comprising the marginal carbon intensity linked to flaring or venting associated with said volume, the marginal carbon intensity linked to flaring or venting associated with said volume being calculated from said respective flaring or venting model,

[0019] - the marginal carbon intensity associated with the last volume produced by said well is equal to the sum of the marginal carbon intensity linked to activation and the marginal carbon intensity linked to pressure support and the marginal carbon intensity linked to flaring or venting, - the respective activation model and / or the respective pressure support model and / or the respective flaring or venting model is revised at a regular interval, the regular interval being inferior to a month, preferably inferior to a day,

[0020] - the method comprises identifying the well or the wells whose marginal carbon intensity is the highest,

[0021] - the method comprises identifying the well or the wells whose marginal carbon intensity is higher than a threshold,

[0022] - the threshold is a fixed marginal emission value or is a marginal emission value corresponding to a given cost,

[0023] - the method comprises the step of further producing, for each well apart from said identified well or wells, at least the respective number of volumes of oil and / or gas during the given period, and further producing, for the or each identified well, a production strictly less than the respective number of volumes of oil and / or gas during the given period,

[0024] - the method comprises sorting the volumes from the volume with the lowest marginal emission to the volume with the highest marginal emission, or the reverse,

[0025] - the method comprises giving a unique ID to each volume of each well and the corresponding marginal emission,

[0026] - the method comprises defining a target, the target comprising a carbon intensity target, the carbon intensity being the emission emitted per produced volume, the method comprising calculating, for at least one well, the production during the given period corresponding to such a carbon intensity target.

[0027] Other features and advantages of the invention will appear upon reading the following description, provided solely as an example and done in reference to the appended drawings, in which:

[0028] - Figure 1 is a schematic view of an example of an oil and / or gas production facility,

[0029] - Figure 2 is a schematic view of examples of steps for calculating carbon intensity,

[0030] - Figure 3 is a schematic view of an example of different steps to calculate the carbon intensity linked to well activation, based on rate,

[0031] - Figure 4 is a schematic view of an example of different steps to calculate the carbon intensity linked to flaring or venting, and

[0032] - Figure 5 is an example of a display displaying the model of the evolution of the production and of the energy intensity of a well depending on the activation.

[0033] An example of an oil and / or gas production facility 10 is represented on figure 1 .

[0034] Said example is very simplified, such as to illustrate the purpose of the description. However, the invention is not limited to such a facility and is adaptable to any desired oil and / or gas production facility. The facility 10 comprising at least one well, more precisely a plurality of wells 12.

[0035] Each well 12 allows the production of oil and / or gas.

[0036] Further, each well 12 produces water.

[0037] Each well 12 is identified using a unique ID.

[0038] At least one or each well 12 is equipped with an activation system 14 for activating the well.

[0039] In the represented embodiment, each well 12 is, for example, equipped such as to allow the activation of the well via gas lift.

[0040] In the case of gas lift, the energy for the activation is, for example, provided by a compressor.

[0041] Alternatively or in complement, some or the wells are equipped with pumping device(s), in order to pump the material to be produced.

[0042] In the case of pump, the energy for the activation is, for example, provided by a power generator or an engine.

[0043] Alternatively or in complement, at least one group of wells is provided with a shared system for well activation, the shared system allowing the activation of the wells of the group. This is, for example, called riser activation, in deep water.

[0044] In that case, the group of wells are considered as a unique well after concatenating the production of the wells of said group after sorting them by increasing multiphasic fluid density, for the rest of the description, in particular for the modeling.

[0045] For example, in a group of two wells, a first well for example produces 1 volume of oil of density 0,8 and 1 volume of water of density 1 , while the second well produces 3 volumes of water for 1 volume of oil. When modeling the intensity of said group of wells, the volumes of the different wells are associated to the multiphasic fluid density associated to the corresponding well. For the first well, it is equal to (0,8+1 ) / 2 = 0,9, while for the second well, it is equal to (0,8+1*3) / 4 = 0,95.

[0046] Moreover, in a particular embodiment, a pressure support system is provided for the well 12.

[0047] The pressure support system injects gas or water inside a well, named injector well, located in the vicinity of the considered well 12, to support the pressure and production of the well 12.

[0048] Wells might support one or more wells 12.

[0049] Well 12 can be supported by one or more wells.

[0050] Each well 12 further comprises a top portion 16 for extracting the material to the surface and transporting it further. Each well 12, in particular the top portion 16, for example, comprises a sensor for measuring the volume produced by the well.

[0051] Alternatively or additionally, the production of each well 12 is estimated, in particular based on regular tests via a test separator or a multiphase flow meter or any other measuring means.

[0052] A model of the relationship between the well activation and the production, corresponding to the volume produced by the well, is, for example, built.

[0053] The model is reassessed regularly, for example based on continuous measured or calculated data or on test. Any deviation, for example, triggers a new series of tests or a readjustment of the model, automatic or manual.

[0054] Additionally and / or alternatively, for each well 12 or group of wells as defined previously, the facility comprises at least one sensor for measuring at least one parameter linked to the consumption of the system for activating the well, by gas lift or pumping.

[0055] The consumption of energy for the activation of each well or group of wells can be calculated from the at least one parameter.

[0056] The at least one sensor, for example, measures the pressure and rate of the gas lift, for gas lift activation, or the power consumption of the pumping device(s), for activation via pumping.

[0057] The consumption of energy for the water injection of each well or group of wells can be calculated from the at least one parameter.

[0058] The at least one sensor, for example, measures the pressure and rate of the water injection, or the power consumption of the pumping device(s).

[0059] Each well 12 further comprises a controller 18 for controlling the parameters of operation of the well 12, in particular at least the parameters relative to the activation of the well.

[0060] In particular, the controller 18 is adapted to control the activation system 14.

[0061] The controllers 18 of the wells 12 are connected to a calculator 20.

[0062] The calculator 20 is adapted to receive data from the controllers, in particular the operating parameters of the activation of the well, and if applicable the measured data from the above mentioned sensors.

[0063] The calculator 20 is for example implemented in the form of a software, or a software brick, executable by a processor.

[0064] In a variant not shown, the calculator 20 is implemented in the form of a programmable logic component, such as an FPGA (Field Programmable Gate Array), or in the form of a dedicated integrated circuit, such as an ASIC (Application Specific Integrated Circuit). When the calculator is implemented as one or more software programs, i.e., as a computer program, it is further adapted to be recorded on a computer-readable medium, not shown. The computer-readable medium is, for example, a medium capable of storing electronic instructions and of being coupled to a bus of a computer system. For example, the readable medium is an optical disk, a magneto-optical disk, a ROM memory, a RAM memory, any type of non-volatile memory (e.g. EPROM, EEPROM, FLASH, NVRAM), a magnetic card or an optical card. A computer program with software instructions is stored on the readable medium.

[0065] Alternatively, the calculator 20 is located remotely, particularly via cloud computing.

[0066] The calculator 20 is adapted to store data in a memory 22.

[0067] The memory 22 is further adapted to store historical data from other sources than the calculator 20, for example from the sensors.

[0068] The memory 22 further comprises models, as will be described in the rest of the description.

[0069] The calculator 20 is adapted to make operations on the received data and the models.

[0070] The facility 10 further comprises a display 24 connected to the calculator 20 for displaying information from the calculator 20.

[0071] The display 24 is connected to the calculator 20 by wire or remotely connected.

[0072] Alternatively, the calculator 20, the memory 22 and the display 24 are not part of the facility 10, but located outside the facility 10, for example in a different location or via cloud computing.

[0073] As mentioned previously, the previously described example of a facility is only given for illustrative reasons.

[0074] The facility 10 of figure 1 will be used to give an example of application of the method according to an embodiment of the invention.

[0075] The method comprises the following steps, as depicted on figure 2:

[0076] - producing 100, for each well 12, a respective number n1 , n2, n3, ... of volumes of oil and / or gas during a given period, and

[0077] - calculating 200, for each well 12, a marginal carbon intensity associated with the last volume produced by said well or said facility or a given sub-group of wells of the facility, here by the calculator 20.

[0078] A volume is, for example, a barrel.

[0079] More particularly, the method comprises calculating, for each well, the carbon intensity associated with each volume of the volumes produced by said well.

[0080] Here, the method comprises calculating, for each well, the energy intensity associated with each volume of the volumes produced by said well, and then the carbon intensity. The marginal carbon intensity associated with a volume produced by a well C.l. tot is, here for example, equal to the sum of the marginal carbon intensity linked to well activation C.l. act and the marginal carbon intensity linked to well pressure support C.l. ps and the marginal carbon intensity linked to flaring or venting C.l. fv.

[0081] Alternatively, the considered marginal carbon intensity associated with a volume produced by a well is, for example, the marginal carbon intensity linked to well activation only, in particular if there is no pressure support, or equal to the sum of the marginal carbon intensity linked to well activation and the marginal carbon intensity linked to well pressure support or to the sum of the marginal carbon intensity linked to well activation and the marginal carbon intensity linked to flaring or venting.

[0082] The consideration of well activation, pressure support and / or flaring or venting depends, for example, on the parameters on which one may act on the facility to reduce emissions and / or to increase the production on a given level of production.

[0083] Calculating the marginal carbon intensity linked to well activation, for example, comprises defining a respective activation model for each well.

[0084] Examples of steps for calculating the carbon intensity linked to well activation, calculated based on the rate, are depicted on figure 3.

[0085] The respective activation model comprises a first model of the variation of the production Prod of said well Wi depending on the energy supplied for the activation E.A., later called energy of activation, of the well.

[0086] The first model is defined by calculating, for each well 12, the relationship between its production level and the associated energy level required for the activation of the well, for each source of activation, here by the calculator 20.

[0087] The respective activation model further comprises a second model of the variation of the emissions associated with the energy needed to supply the activation Act EmAct depending on the activation Act of the well 12.

[0088] The marginal carbon intensity linked to well activation associated with a volume is calculated from said respective activation model.

[0089] Here, the first model is previously interpolated such that the curve is continuous and its derivative is continuous.

[0090] The maximum of production obtainable according to the first model, and the corresponding energy (or energies) of activation is determined.

[0091] If, in the first model, the production is not strictly increasing when the energy supplied for the activation E.A. increases, only the curve for an energy supplied for the activation E.A. below the only or the smallest energy of activation for obtaining the maximum of production is considered. For each well 12, the first model is then inverted such as to provide a relationship of the energy of activation depending on the production, up to the maximum of production.

[0092] Said relationship is, for example, resampled.

[0093] Resampling is, here, interpolating and resampling with a regular scale per volume.

[0094] Said relationship is, for example, smoothed.

[0095] Smoothing is, here, locally ensuring that the global interpolated curve is convex (second derivative always positive or null), under the control of mean square root error calculation. The smoothing is generally imperceptible on the interpolated curve, but beneficial to have a regular (and monotone) derivative trend.

[0096] For each well 12, the obtained relationship is then derived to obtain the energy intensity E.l. linked to the energy of activation depending on the production.

[0097] The energy of activation E.A. depending on the production Prod of all the wells ZWi of the facility are then concatenated.

[0098] The production is separated in volumes and the corresponding produced volumes are sorted out from the volume with the lowest activation energy intensity to the volume with the highest activation energy intensity, or the reverse, here by the calculator 20.

[0099] More particularly, the volumes are sorted based on the energy intensity, while respecting the order of said volumes within each well. In particular, the n+1 th volume of a well comes after the nth volume of said well, even in the case where the energy intensity would not be increasing.

[0100] Circumstances leading to a not increasing energy intensity are limited.

[0101] This aspect is later resolved via the convex hulling, described thereafter.

[0102] Each well being identified using a unique ID, the sorted volumes are also identified, such as to easily visualize which wells have the highest energy intensity for the considered volume.

[0103] The second model is then composed with the previously obtained function of the energy of activation depending on the production of all the wells of the facility, to obtain the variation of the emissions linked to activation EmAct depending on the production Prod.

[0104] If the obtained function is locally not convex, then a convex hulling of the curve is applied to the whole curve.

[0105] The method further comprises deriving the convex hulled curve, in order to calculated the corresponding carbon intensity.

[0106] For all the volumes for which the convex hulling did not modify the value, the carbon intensity C.l. linked to well activation, calculated based on the rate, is equal to the derivative of the emissions linked to activation of said volume. For all the volumes for which the convex hulling modified the value, the carbon intensity C.l. linked to well activation, calculated based on the rate, is equal to the carbon intensity linked to activation, calculated based on the rate, of the following volume for which the convex hulling did not modify the value.

[0107] The carbon intensity linked to well activation is, for example, equal to the carbon intensity linked to well activation calculated based on the rate, for example when the well activation is provided by pumps or when the needed pressure of the well activation through gas lift is not significantly different for the different wells.

[0108] For a well without an activation system, the carbon intensity linked to activation is null.

[0109] In some embodiments, a carbon intensity linked to well activation calculated based on the pressure is also considered to calculate the carbon intensity linked to well activation.

[0110] For example, at least one well imposes a pressure for well activation, for example by gas lift, strictly greater than the other wells of the facility.

[0111] A relationship between the injection pressure needed for the well activation and the production is calculated at the facility level, in particular by only considering the gas lift injection pressure needed to obtain the volumes corresponding to a production level.

[0112] More particularly, said relationship is known at well level, and then sorted and concatenated at facility level.

[0113] The pressure to obtain a given injection rate is known.

[0114] The relationship between the rate needed for the well activation, based on pressure, and the production is known.

[0115] The relationship between the pressure needed for the well activation and the production is calculated at the facility level.

[0116] The volumes are sorted by pressure, here by the calculator 20.

[0117] More particularly, the volumes are sorted based on the pressure, while respecting the order of said volumes within each well. In particular, the n+1 th volume of a well comes after the nth volume of said well, even in the case where the gas lift pressure would not be increasing.

[0118] The curve of the energy of activation in regard to said pressure depending on the production, with the volumes as previously sorted out, is then calculated.

[0119] The second model is then composed with the previously obtained function of the energy of activation depending on the production of all the wells of the facility, to obtain the variation of the emissions linked to activation EmAct depending on the production Prod.

[0120] If the obtained curve is not convex, then a convex hulling of the curve is applied. For all the volumes for which the convex hulling did not modify the value, the carbon intensity linked to well activation, calculated based on the pressure, is equal to the derivative of the emissions needed for the well activation, based on pressure, of said volume.

[0121] For all the volumes for which the convex hulling modified the value, the carbon intensity linked to well activation, calculated based on the pressure, is equal to the carbon intensity linked to well activation, based on pressure, of the following volume for which the convex hulling did not modify the value.

[0122] The carbon intensity linked to well activation is then equal to the maximum between the carbon intensity linked to well activation calculated based on the rate and the carbon intensity linked to well activation calculated based on the pressure.

[0123] For a well without an activation system, the carbon intensity linked to activation is null.

[0124] Calculating the marginal carbon intensity linked to pressure support, for example, comprises defining a respective pressure support model for each well.

[0125] The respective pressure support model comprises a first model connecting the production of the well to the energy supplied for the pressure support depending.

[0126] Said energy, for example, corresponds to a volume of water pushed downhole, said volume requiring energy.

[0127] For example, the variation of production depending on the well pressure is known, as well as how the volumes injected for pressure support influence the well pressure, and the variation of the energy supplied for the pressure support and the injected volume.

[0128] Thus, by composition of the functions, the variation of the production of the well depending on the energy supplied for the pressure support may be known.

[0129] The respective pressure support model further comprises a second model of the variation of the emissions associated with the volume supplied for pressure support to a well or group of wells, depending on the energy supplied for pressure support, i.e on the volumes supplied and the required injection pressure to inject it into the reservoir.

[0130] The marginal carbon intensity linked to pressure support associated with a volume is calculated from said respective pressure support model.

[0131] Calculating the marginal carbon intensity linked to pressure support based on the rate comprises steps similar to that for calculating marginal carbon intensity linked to well activation based on the rate, as will be described below.

[0132] Here, the first model is previously interpolated such that the curve is continuous and its derivative is continuous.

[0133] The maximum of production obtainable according to the first model, and the corresponding energy (or energies) for pressure support is determined. If, in the first model, the production is not strictly increasing when the energy supplied for the pressure support increases, only the curve for an energy supplied for the pressure support below the only or the smallest energy for the pressure support for obtaining the maximum of production is considered.

[0134] For each well 12, the first model is then inverted such as to provide a relationship of the energy of pressure support depending on the production, up to the maximum of production.

[0135] Said relationship is, for example, resampled.

[0136] Resampling is, here, interpolating and resampling with a regular scale per volume.

[0137] For each well 12, the obtained relationship is then derived to obtain the energy intensity linked to the energy for the pressure support depending on the production.

[0138] The energy for the pressure support depending on the production of all the wells of the facility are then concatenated.

[0139] The production is separated in volumes and the corresponding produced volumes are sorted out from the volume with the lowest pressure support energy intensity to the volume with the highest pressure support energy intensity, or the reverse, here by the calculator 20.

[0140] More particularly, the volumes are sorted based on the energy intensity, while respecting the order of said volumes within each well. In particular, the n+1 th volume of a well comes after the nth volume of said well, even in the case where the energy intensity would not be increasing.

[0141] Circumstances leading to a not increasing energy intensity are limited.

[0142] This aspect is later resolved via the convex hulling, described thereafter.

[0143] Each well being identified using a unique ID, the sorted volumes are also identified, such as to easily visualize which wells have the highest energy intensity for the considered volume.

[0144] The second model is then composed with the previously obtained function of the energy for the pressure support depending on the production of all the wells of the facility, to obtain the variation of the emissions for the pressure support depending on the production.

[0145] If the obtained function is locally not convex, then a convex hulling of the curve is applied to the whole curve.

[0146] The method futher comprises deriving the convex-hulled curve, in order to calculate the corresponding carbon intensity.

[0147] For all the volumes for which the convex hulling did not modify the value, the carbon intensity for the pressure support, calculated based on the rate, is equal to the derivative of the emissions for the pressure support of said volume. For all the volumes for which the convex hulling modified the value, the carbon intensity for the pressure support, calculated based on the rate, is equal to the carbon intensity linked to the pressure support, calculated based on the rate, of the following volume for which the convex hulling did not modify the value.

[0148] The carbon intensity linked to pressure support is, for example, equal to the carbon intensity linked to pressure support calculated based on the rate.

[0149] A carbon intensity linked to pressure support calculated based on the pressure is here, for example, also considered.

[0150] For example, at least one well imposes a pressure for pressure support, strictly greater than the other wells of the facility.

[0151] A relationship between the injection pressure needed for the pressure support and the production is calculated at the facility level, in particular by only considering the pressure needed to obtain the volumes corresponding to a production level.

[0152] More particularly, said relationship is known at well level, and then sorted and concatenated at facility level.

[0153] The pressure to obtain a given rate is known.

[0154] The relationship between the rate needed for the pressure support, based on pressure, and the production is known.

[0155] The relationship between the pressure needed for the pressure support and the production is calculated at the facility level.

[0156] The volumes are sorted by pressure, here by the calculator 20.

[0157] More particularly, the volumes are sorted based on the pressure, while respecting the order of said volumes within each well. In particular, the n+1 th volume of a well comes after the nth volume of said well, even in the case where the gas lift pressure would not be increasing.

[0158] The curve of the energy of activation in regard to said pressure depending on the production, with the volumes as previously sorted out, is then calculated.

[0159] The second model is then composed with the previously obtained function of the energy of pressure support depending on the production of all the wells of the facility, to obtain the variation of the emissions linked to pressure support depending on the production.

[0160] If the obtained curve is not convex, then a convex hulling of the curve is applied.

[0161] For all the volumes for which the convex hulling did not modify the value, the carbon intensity linked to pressure support, calculated based on the pressure, is equal to the derivative of the emissions needed for the pressured support, based on pressure, of said volume. For all the volumes for which the convex hulling modified the value, the carbon intensity linked to pressure support, calculated based on the pressure, is equal to the carbon intensity linked to pressure support, based on pressure, of the following volume for which the convex hulling did not modify the value.

[0162] The carbon intensity linked to pressure support is then equal to the maximum between the carbon intensity linked to pressure support calculated based on the rate and the carbon intensity linked to pressure support calculated based on the pressure.

[0163] Examples of steps for calculating the carbon intensity linked to flaring or venting are depicted on figure 4.

[0164] Considering that in some occasions flaring or venting is associated to characteristics of the well, like its water cut or gas oil ratio, which impact the quantity of gas not marketable (contaminated, potentially beyond export capacity, etc...) or not processable (contamination, degassed in parts of the process where it cannot be recompressed...), models for such quantity of gas are built for each well.

[0165] The volumes of the wells are sorted based on the gas oil ratio (GOR) of the corresponding well.

[0166] The function of the produced gas GProd depending on the production Prod, in which the volumes are sorted based on the GOR, is calculated.

[0167] The emissions linked to the flaring or venting of the excess quantity of production depending on the production are calculated.

[0168] The carbon intensity linked to flaring or venting at the facility level is equal to the derivative of the emissions linked to the flaring or venting previously calculated.

[0169] The carbon intensity C.l. linked to flaring or venting at the facility level is redistributed to the volume(s) for which the production of gas is in excess, starting with the volume(s) with the highest GOR and decreasing.

[0170] If no flaring or venting is done for a given level of production, then the carbon intensity relative to flaring or venting for said production is null.

[0171] The respective models are revised at a regular interval, the regular interval being inferior to a month, preferably inferior to a week, preferably inferior to a day, in particular inferior to five hours, in particular inferior to an hour.

[0172] In particular, the models are compared, here by the calculator 20, with the data measured by the sensors equipping the well 12. In case of a difference, the method comprises adjusting the models to approximate the measured data, here by the calculator 20.

[0173] The well evolves with time, such that adapting the models allow results to be more accurate. In an embodiment, the method comprises identifying the well or the wells whose marginal emissions associated with the last volume is the highest, here by the calculator 20.

[0174] Alternatively, the method comprises identifying the well or the wells whose marginal emission associated with the last volume is higher than a threshold, here by the calculator 20.

[0175] Thus, the last volumes which high associated emissions, for each well and at the facility level, are identified.

[0176] The threshold is, for example, a fixed marginal emission value.

[0177] Alternatively, the threshold is a marginal emission value corresponding to a given cost.

[0178] The cost comprises, in particular is constituted from, the cost to produce said volume and the opportunity value of the activation energy and pressure support energy, should the corresponding CO2 allowance or credit been sold instead.

[0179] In one embodiment, the cost of producing the volume is further combined to a variablecost model of the volume, for example including chemical products.

[0180] Said threshold cost, for example, depends on the market of the oil and / or gas.

[0181] The method then comprises the following steps:

[0182] - further producing, for each well apart from said identified well or wells, the respective number of volumes of oil and / or gas during the given period, and

[0183] - further producing, for the or each identified well, a production less than or equal to the respective number minus one of volumes of oil and / or gas during the given period.

[0184] Thus, the operation of the facility is adapted such that the last volumes that were identified as having particularly high associated emissions to produce during the given period are not produced.

[0185] In an embodiment, for the or each identified well, said further producing step corresponds to producing a production equal to the respective number minus one of volumes of oil and / or gas during the given period.

[0186] Similarly as previously, some volumes are identified, for example by having the highest marginal emission or by having a marginal emission superior to a threshold.

[0187] The operation of the facility is thus adapted such that the identified volumes are thus not produced in the future.

[0188] Said calculating step and said step of identifying volumes having a marginal emission higher than a threshold is, for example, reiterated, here by the calculator 20, as long as some volumes are identified.

[0189] Then, the facility is operated such that all the identified volumes are not produced by said wells consequently during the given period. Thus, the last volumes that were identified as having particularly high associated emissions to produce during the given period are not produced.

[0190] In the mark of curtailing production for group of wells due to high activation Carbon Intensity, in the case of a group of wells, the volumes not to be produced are the ones with the highest multiphasic fluid density.

[0191] The activation energy and / or injection volumes, that are available due to the volumes previously produced by the identified well(s), are, for example, reallocated in the operation of the facility to other well(s), for example if:

[0192] - the marginal emission associated with producing one more volume with the well is strictly inferior to the marginal emission associated with the last volume of the identified well, or

[0193] - the marginal emission associated with producing one more volume with the well is strictly inferior to the threshold, or

[0194] - the marginal emission associated with producing one more volume with the well is strictly inferior to a second threshold.

[0195] Said conditions are, for example, directly deduced from the carbon intensity calculated for said additional volume of the well.

[0196] Said second threshold is, for example, strictly inferior to the threshold to identify wells, if applicable.

[0197] The well(s) to which are reallocated the activation energy and / or pressure support injection volumes are, for example, the well(s) for whom the marginal emission associated with producing one more volume with said well is the lowest.

[0198] Alternatively, the method comprises transferring a first number of volumes produced by the identified well(s) as having particularly high carbon intensity for the last volume(s) to a second number of volumes produced by a well or wells having lower or the lowest marginal carbon intensity, such as to have a constant carbon intensity at the facility level. The second number is strictly superior to the first number.

[0199] In the embodiment in which the method comprises calculating, for each well, the carbon intensity associated with each volume produced by each well, the method for example further comprises sorting all the volumes from all the wells from the volume with the lowest carbon intensity to the volume with the highest carbon intensity, or the reverse, here by the calculator 20.

[0200] As mentioned previously, the considered carbon intensity may include the impact of well activation, pressure support and / or flaring or venting. This allows making particular recommendations, such as not producing a given volume from a given well or transferring activation energy and / or injection volumes to another well as detailed previously, based on the different considered factors.

[0201] In one embodiment, the method further comprises defining a target, the target comprising a carbon intensity target, in particular for a well.

[0202] The method comprises calculating, for at least one of the wells, for example for each well, the production during the given period corresponding to such a carbon intensity target, here by the calculator 20.

[0203] On figure 5, is represented at a point K1 , the current setting of operation of the well, corresponding to the respective number of volumes of oil and / or gas during a given period.

[0204] A plurality of targets K2, K3, K4, corresponding to a mean carbon intensity for the well, are here defined.

[0205] The production corresponding to each carbon intensity target is here calculated.

[0206] In particular, in the depicted embodiment, the activation Act corresponding to the carbon intensity equal to the target is calculated, and thus the corresponding production Prod during the given period.

[0207] The calculator 20, for example, further calculates how many volumes are not to be produced compared to the current setting K1 to reach said target.

[0208] The calculator 20, for example, further calculates the amount of saved emission corresponding to said target compared to the current setting K1 , during a projection period.

[0209] Furthermore, the calculator 20, for example, calculates the associated saved cost.

[0210] The associated saved cost comprises, in particular is constituted from, the cost to produce said volume and the opportunity value of the activation energy and pressure support energy, should the corresponding CO2 allowance or credit been sold instead.

[0211] In one embodiment, the cost of producing the volume is further combined to a variablecost model of the volume, for example including chemical products.

[0212] The projection period is, for example, strictly superior to the given period.

[0213] The projection period is, for example, equal to a year.

[0214] This enables visualizing the beneficial impact associated with the target, in relation to the measures to be taken to achieve it.

[0215] A plurality of targets may be defined, such that they can be compared, in particular regarding the ratio between the beneficial impact and the impact on the production of the well.

[0216] The method, for example, further comprises storing in the memory 22: the model of each well, in particular in case of an adjustment, the different measured marginal emission, the identified wells and / or volumes. The method, for example, further comprises displaying on the display 24 a list of the wells of the facility and, for example, if one well is selected, as depicted on figure 5, at least one of the following elements: the model of the well, the point K1 on the model corresponding to the current setting of operation of the well, the marginal emission associated with the last volume, and / or the target(s) K2, K3, K4 on the model and eventually the volumes not to be produced to reach said target and / or the saved emissions during the projection period and / or the cost intensity of the last volume.

[0217] Thus, the method of the invention allows identifying volumes that are associated with particularly high emissions, in order to adapt the operation of the facility such as not to produce such high emissions.

Claims

CLAIMS1.- Method for operating a given facility (10) of oil and / or gas production, the given facility comprising at least one well (12), the method comprising the following steps:- producing, for each well (12), a respective number of volumes of oil and / or gas during a given period, and- calculating, for each well (12), a marginal carbon intensity associated with the last volume produced by said well (12) or said facility (10) or a given sub-group of wells of the facility (10).2.- Method according to claim 1 , comprising calculating, for each well (12), the carbon intensity associated with each volume of the volumes produced by said well (12).3.- Method according to claim 1 or 2, comprising calculating a marginal carbon intensity linked to activation associated with said volume based on rate, said calculating comprising defining a respective activation model for each well, the respective activation model comprising a first model of the variation of the production (Prod) of said well (12) depending on the energy supplied for the activation (E.A.) of the well (12) and a second model of the variation of the emissions associated with the energy needed to supply the activation (Act) depending on the activation (Act), the marginal carbon intensity associated with one volume produced by said well (12) comprising the marginal carbon intensity linked to activation associated with said volume.4.- Method according to claim 3, comprising determining for each well or for all wells of the facility, from the respective activation model, the emissions associated with the activation of the well or wells depending on the production.5.- Method according to claim 3 or 4, comprising calculating a marginal carbon intensity linked to activation associated with said volume based on pressure, the marginal carbon intensity linked to activation associated with a volume being equal to the maximum between the marginal carbon intensity linked to activation base on rate and the marginal carbon intensity linked to activation based on the pressure.6.- Method according to any one of claims 1 to 5, comprising calculating a marginal carbon intensity linked to pressure support associated with said volume based on rate, said calculating comprising defining a respective pressure support model for each well, the respective pressure support model comprising a first model of the energy supplied forpressure support depending on the production of the well (12) and a second model of the variation of the emissions associated with the energy supplied for pressure support depending on the energy supplied for pressure support, the marginal carbon intensity associated with a volume produced by said well (12) comprising the marginal carbon intensity linked to the pressure support associated with said volume.7.- Method according to claim 6, comprising determining for each well or for all wells of the facility, from the respective pressure support model, the emissions associated with the pressure support of the well or wells depending on the production.8.- Method according to claim 6 or 7, comprising calculating a marginal carbon intensity linked to pressure support associated with said volume based on pressure, the marginal carbon intensity linked to pressure support associated with a volume being equal to the maximum between the marginal carbon intensity linked to pressure support based on rate and the marginal carbon intensity linked to pressure support based on the pressure9.- Method according to any one of claims 1 to 8, comprising defining a respective flaring or venting model for each well, the respective flaring or venting model comprising a model of the quantity of gas produced depending on the production, the marginal carbon intensity associated with a volume comprising the marginal carbon intensity linked to flaring or venting associated with said volume, the marginal carbon intensity linked to flaring or venting associated with said volume being calculated from said respective flaring or venting model.10.- Method according to claims 3 or 4 or 5, and 6 or 7 or 8, and 9, wherein the marginal carbon intensity associated with the last volume produced by said well (12) is equal to the sum of the marginal carbon intensity linked to activation and the marginal carbon intensity linked to pressure support and the marginal carbon intensity linked to flaring or venting.1 1.- Method according to any of claims 3 to 10, wherein the respective activation model and / or the respective pressure support model and / or the respective flaring or venting model is revised at a regular interval, the regular interval being inferior to a month, preferably inferior to a day.12.- Method according to any of claims 1 to 1 1 , comprising identifying the well or the wells (12) whose marginal carbon intensity is the highest.13.- Method according to any of claims 1 to 1 1 , comprising identifying the well or the wells (12) whose marginal carbon intensity is higher than a threshold.14.- Method according to claim 13, wherein the threshold is a fixed marginal emission value or is a marginal emission value corresponding to a given cost.15.- Method according to any of claims 9 to 14, comprising the step of further producing, for each well apart from said identified well or wells, at least the respective number of volumes of oil and / or gas during the given period, and further producing, for the or each identified well, a production strictly less than the respective number of volumes of oil and / or gas during the given period.16.- Method according to any one of claims 1 to 15, comprising sorting the volumes from the volume with the lowest marginal emission to the volume with the highest marginal emission, or the reverse.17.- Method according to claim 16, comprising giving a unique ID to each volume of each well (12) and the corresponding marginal emission.18.- Method according to any one of claims 1 to 17, comprising defining a target (K2, K3, K4), the target (K2, K3, K4) comprising a carbon intensity target, the carbon intensity being the emission emitted per produced volume, the method comprising calculating, for at least one well, the production during the given period corresponding to such a carbon intensity target.

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