RU2666280C1 - Method of casing results of measurements of core filtration-capacity properties and geophysical research on the well depth - Google Patents

Abstract

FIELD: oil and gas industry.SUBSTANCE: invention relates to the oil and gas industry and makes it possible to coordinate the filtration-capacity properties (FCP) of the rock in the depth of the well. Method of linking the results of measurements of the filter-capacitance properties of core and geophysical studies of wells in depth includes conducting geophysical studies of wells at wells and core sampling with subsequent determination of filtration-capacitance properties on samples, pre-processing of core data, construction of a table for correlating data on the core, creation of a matrix of deviations in the values of the filtration and capacitance properties from the core and from the data of geophysical studies of wells for current and overlying samples, in which the number of rows of the matrix corresponds to the number of samples in the correlations data table, number of columns – the number of measurements of geophysical studies of wells in depth. Determine the depths of all the samples in question, ensuring a minimum discrepancy between the values of the filtration and capacitance properties of the core and geophysical studies of the wells.EFFECT: technical result of the invention is to provide an on-line evaluation of reservoir properties by automating the core casing and geophysical well logging (GWL) process.1 cl, 1 dwg

Description

The invention relates to the oil and gas industry and allows you to align the depth of the well of the data of reservoir properties (FES) of the rock, determined on core samples, to the curves of the FES calculated according to the results of geophysical studies of wells (GIS). By linking is meant the determination of the depth of core samples so that the FES of core samples correspond to the FES according to GIS at these depths.

In the process of interpreting GIS data, the task often arises of comparing the results of direct measurements on core samples and indirect values obtained from the GIS. For the correct comparison, it is necessary that the depths of core sampling and well logging coincide. Often there is a mismatch of depths in core and GIS. There are several reasons for the occurrence of this situation, the main of which are the mismatch of depths on the selection string and the wireline, as well as incomplete removal. The core is selected in the form of a column, part of the rock crumbles and is lost. The remaining pieces are stacked in boxes sequentially, without gaps, together they form a takeaway. Due to the loss of part of the core, uncertainty arises in determining the depth of sampling. The lower the percentage of removal, the higher this uncertainty. Due to the high uncertainty in determining the initial position of the samples, low-core cores are not, in practice, linked to well logging. As a result, a significant part of the core information may not be taken into account.

There are various ways of automated linking of core and GIS data in depth using software tools.

A known method of automated linking of core data and electric logging in depth, implemented in the computer method of organizing and processing information (US 8.577.614 B2, IPC G06F 15/00, published 05.11.2013). The method includes preliminary recording of information on core and electric logging, their subsequent linking using the correlation module and displaying the results of the link in order to assess the quality.

Software is known from the prior art that allows linking core and GIS data in depth:

Fontana E., Iturrino GJ, Tartarotti P. Depth-shifting and orientation of core data using a core-log integration approach: A case study from ODP-IODP Hole 1256D Original Research Article // Tectonophysics, Volume 494, Issues 1-2, October 29, 2010, pp. 85-100.

Agrinier P., Agrinier B. On the knowledge of the depth of a rock sample from a drilled core // Comptes rendus de l'Academie des sciences. Serie 2, Mecanique, physique, chimie, sciences de l'univers, sciences de la terre, 318 (12), 1994, pp. 1615-1622.

[website]. URL: http://geoglobesoft.ru.

[website]. URL: http://prime.geotec.ru

[website]. URL: http://www.amplituda.ru/en/petrophysics/Progrobesp/saphir.html

[website]. URL: http://pangea.ru/en/index.php?option=com_content&task=view&id=20&Itemid=23

[website]. URL: http://sis.slb.ru/sis/techlog

[website]. URL: http://www.ldeo.columbia.edu/BRG/ODP/ODP/CLIP/clip.html

Moreover, in well-known methods, not FES on core samples is linked, but core logs and well logs. Therefore, the disadvantage of the known methods is the limited application for the old well stock, where core data are not available.

The objective of the invention is to automate the process of linking the results of the measurement of FES on the core to the FES data on the GIS.

The technical result of the invention is the provision of a rapid assessment of the properties of the reservoir by automating the process of linking to core and well logging.

The technical result is achieved by the fact that the method of linking the results of measurements of the reservoir properties of the core and geophysical studies of the wells in depth includes conducting geophysical studies of wells in the wells and core sampling with subsequent determination of the reservoir properties of the samples, pre-processing of core data, building a table of data linking settings for core containing information on samples obtained as a result of measurements of FES for core, as well as for fictitious samples corresponding to the beginning and at the end of sampling intervals, in which weights for core samples are set, restrictions on possible shift intervals for core removal intervals, samples within sampling intervals, groups of jointly shifted samples are determined, types of shifts: relative to overlying samples and relative to the current position of the samples, as well as intervals of possible the distance between the samples, creating a matrix of deviations of the values of the reservoir properties according to the core and according to the data of geophysical studies of wells for the current and overlying x samples, in which the number of matrix rows corresponds to the number of samples in the core data linking settings table, the number of columns corresponds to the number of depth measurements of geophysical surveys of wells, while on each row of the matrix values are determined only for elements within possible shift intervals relative to the initial position , for which the values of the elements on the first line are filled with zeros, because the first sample always corresponds to the beginning of the sampling interval - a fictitious sample, the values on the following lines are determined based on the values on the previous lines, for this, for each possible position of the sample, the values of the deviations of the reservoir properties according to the core and geophysical studies of the wells for the current position of the sample are calculated, multiplied by the value of the corresponding weight coefficient of the sample and determine the position of the sample at the previous level, giving the minimum amount of deviations, taking into account the limited the distance between the samples specified in the settings table and the length of the sampling interval, using auxiliary matrices of a similar structure, which record the possible positions of the first sample of the current sampling interval in the deviation matrix and the position of the sample at the previous level for all subsequent rows, after which determine the position of the last core sample from the adjustment settings table with the minimum value of the sum of deviations, and determine the depth by the found position, then determine the position of the sample on the previous line using the data of the auxiliary matrix, respectively, determine the depths of all samples under consideration, ensuring the minimum discrepancy between the values of the filtration-capacitive properties for core and geophysical studies of wells.

In addition, in the absence of some of the data on reservoir properties for geophysical surveys of wells, the weighted amounts of deviations are compared taking into account the number of accumulated samples; for this, an additional auxiliary matrix is used to record the number of samples included in the calculation of the sum of deviations of the values of reservoir properties according to core and according to the results of geophysical research of wells for each considered position of the sample.

The invention is illustrated by graphic materials, where in FIG. depicts a general block diagram of the algorithm of the program for linking the data of FES for core and GIS

The proposed method formalizes the linking process by constructing a table of settings for linking core data and matrices characterizing various positions of core samples. Therefore, it allows you to implement the linking process using computer programs.

Laboratory core tests are direct methods for studying reservoir properties. The core is selected as a column. Cylindrical samples are cut from it, on which the FES measurements are performed. Each sample has its own sampling depth and refers to a certain removal interval. Advances can be uniform for the entire offset interval. This situation is characteristic in the case of a high percentage of removal. Also, linking can be done within the offset interval itself. The intervals of the movements can be determined based on the percentage of removal.

GIS data refers to indirect measurement methods. As a result of their interpretation, synthetic curves characterizing the properties of the formation are obtained.

Typically, the data from the results of laboratory core tests are presented in the form of a table containing the following columns: the name of the well, the depth of the start of the sampling interval, the depth of the end of the sampling interval, the percentage of removal and the depth of sampling, data from the Federal State Statistics Service. GIS data are presented in the form of curves containing information about the depth of each measurement and the value of the measured value at a given depth. Linking is carried out by searching for the magnitude of the shifts of each core sample, so that the FES values for the core after linking match the values of the FES obtained from the GIS as much as possible.

To implement the proposed method of linking the main input data is a table of the results of laboratory tests of the core after pre-processing and GIS data. Pre-processing of core data involves converting them to form when a specific depth is characterized by a single value of a specific FES. For this, for example, take the median value of the FES of all samples with the current depth of the place of sampling.

Based on the table of results of laboratory core research, a table of settings for linking core data is built, containing the following columns: well name, depth of the start of the sampling interval, depth of the end of the sampling interval, percentage of removal, depth of sampling, columns with FES values and weight coefficients for each sample and FES corresponding to the values of the weights w _i , where i is the serial number of the sample. The following columns indicate: type of sample (initial, fictitious, corresponding to the beginning of the sampling interval - “roof”, fictitious, corresponding to the end of the sampling interval - “sole”), minimum distance to the overlying sample, maximum distance to the overlying sample, group number samples, range of shift up, range of shift down, type of shift (absolute or relative).

The values of the weight coefficients w _i for dummy samples are set equal to zero.

The values in the column “minimum distance to the overlying sample” are defined as the current distance to the overlying sample, it can be equal to zero only if it is the first sample of the sampling interval or a fictitious sample “roof” or “sole”, because initial samples cannot overlap each other, their order is preserved. These values allow us to take into account the “incompressibility” of the distance between the samples within the sampling interval.

The values in the column "maximum distance to the overlying sample" are calculated taking into account the percentage of removal according to the formula, which is the sum of the minimum distance to the previous sample and the product of the length of the sampling interval by the fraction of the undeveloped part, for all samples except for the type of "sole",

,

,

- длина интервала отбора;Where

- the length of the selection interval;

s _min - the minimum distance to the overlying sample;

s _max - the maximum distance to the overlying sample.

If the value of the percentage of removal is not defined, for calculations consider the value of 100%. For a fictitious “sole” sample, the maximum distance is calculated as the distance from the lower sample of the interval to the depth of the end of the sampling interval.

Samples with the same group number are linked together, i.e. the original distance between the samples is maintained. In this case, the values from the columns indicating the type of shift, the range of the shift up, the range of the shift down are ignored for all samples except the first in the group. In case of interval linking, the fictitious “roof” sample has a number 1 less than the other removal samples. This allows for offset movements within the sampling interval. If the fictitious “roof” sample has the same group number as the other offset samples, then the entire interval will move in its entirety, without movement within the sampling interval. For point-to-point linking within the sampling interval, each sample must be assigned its own group number.

The relative type of shift is the shift relative to the current distance to the last sample of the previous group. The absolute type of shift is the shift of the relative current position of the sample without taking into account the distance to neighboring groups of samples.

The next step in the linking method is to create a matrix of deviations of the FES values for the core and GIS F, the number of rows of which corresponds to the number of samples in the settings table for the core, and the number of columns to the number of GIS measurements in depth. When creating the matrix F, values are determined only for elements within the possible intervals of shifts relative to the initial position of the sample.

положении первого образца интервала отбора, а также F_count, где записывают количество образцов, подлежащих суммированию при расчете суммы отклонений ФЕС по керну и ГИС, при этом суммирование осуществляют после умножения на соответствующие значения весовых коэффициентов w_i. Значения элементов матрицы F_count не всегда соответствуют количеству строк, т.к. некоторые образцы могут относиться к интервалам, в которых значения ФЕС по ГИС не определены. В этом случае суммирование не осуществляют.Additionally create auxiliary matrices of a similar structure: the matrix F_idx containing information about the position of the element on the previous row,

the position of the first sample of the sampling interval, as well as F_count, where the number of samples to be added is calculated when calculating the sum of the deviations of the FES for core and logging data, and the summation is carried out after multiplying by the corresponding values of the weight coefficients w _i . The values of the elements of the matrix F_count do not always correspond to the number of rows, because some samples may relate to intervals in which the FES values for GIS are not defined. In this case, the summation is not carried out.

определяют как текущее положение элемента. Исходя из исходных положений образцов, положений образцов на предыдущей строке, а также значений параметров из таблицы настроек увязки данных по керну: «диапазон сдвига вверх», «диапазон сдвига вниз», «минимальное расстояние до вышележащего образца», «максимальное расстояние до вышележащего образца», «тип образца», «глубина начала интервала отбора», «глубина конца интервала отбора» - определяют возможные положения образцов, начиная со второй строки, вычисляют значения отклонений ФЕС по керну и ГИС для текущего положения образца, умножают на значения весового коэффициента для текущего образца, и определяют положение образца на предыдущей строке, дающее минимальную сумму отклонений, с учетом ограничений на расстояние между образцами и на длину интервала выноса. Во вспомогательную матрицу F_idx записывают положение образца на предыдущем уровне, в матрицу F_count - количество суммируемых элементов, в матрицу

- значение для определенного образца на предыдущем уровне, если образец принадлежит тому же интервалу отбора, и текущее положение образца, если это фиктивный образец «кровля».The values of the elements on the first row of the matrix F for all possible positions of the sample are filled with zeros, because the first sample is always a fictitious “roof” sample with a weight coefficient of zero. Then, the current positions of the samples are recorded in the auxiliary matrix F_idx, and the corresponding values in the auxiliary matrix F_count are set to unity, in the matrix

defined as the current position of the element. Based on the initial positions of the samples, the positions of the samples on the previous line, as well as the values of the parameters from the table of settings for linking core data: “shift range up”, “shift range down”, “minimum distance to the overlying sample”, “maximum distance to the overlying sample "," Type of sample "," depth of the beginning of the sampling interval "," depth of the end of the sampling interval "- determine the possible positions of the samples, starting from the second line, calculate the values of the deviations of the FES from the core and GIS for the current position of the sample, multiplying dissolved in the weight value for the current sample, and determine the position of the sample on the previous line, which gives the minimum sum of deviations with the limitations on the distance between the samples and the length of the interval removal. The position of the sample at the previous level is recorded in the auxiliary matrix F_idx, in the matrix F_count - the number of elements to be summed, in the matrix

- the value for a particular sample at the previous level, if the sample belongs to the same sampling interval, and the current position of the sample, if it is a fictitious “roof” sample.

After calculating the values of the elements of the deviation matrix of the FES values for the core and well logs and auxiliary matrices, the position of the last core sample is determined from the adjustment settings table with the minimum value of the sum of the deviations, its depth is determined from the found position.

Then, sequentially determine the position of the sample on the previous line using the data of the auxiliary matrix F_idx, respectively, determine the depths of all considered samples, ensuring minimal discrepancy between the values of the FES in core and well logging. In this way, the results of measurements of the core and well logging measurements along the depth of the well are carried out.

In the general case, the F_count matrix data are not used, but in the case when a part of the FES data on the GIS is missing, when calculating the sum of the deviations, the number of summed samples is taken into account. When searching for an element at the previous level, a comparison is made of the sums of deviations divided by the number of summed samples.

A specially designed computer program allows you to carry out the described procedure for determining the depths of samples in an automated mode. The input data for the computer program are the table of the results of laboratory tests of the core and the FES data on the GIS. The linking algorithm is reduced to finding the optimal position of the sample based on the calculation and comparison of the quality function between the possible positions of the samples. At the output, the program provides core samples data, linked in depth, and reports on the results of linking.

Claims (2)

1. A method for linking the results of measurements of the reservoir properties of the core and depth geophysical surveys of wells includes conducting geophysical surveys of wells in the wells and core sampling, followed by determining the reservoir properties of the samples, pre-processing core data, building a table of settings for linking core data containing information on samples obtained as a result of measurements of FES by core, as well as fictitious samples corresponding to the beginning and end of sampling intervals, in which I set t weight coefficients for core samples, restrictions on possible shift intervals for core removal intervals, samples within sampling intervals, determine groups of jointly shifted samples, types of shifts: relative to overlying samples and relative to the current position of the samples, as well as the intervals of possible distances between samples, creating a deviation matrix values of filtration-capacitive properties according to the core and according to the data of geophysical studies of wells for current and overlying samples, in which the number of lines is mat the number of samples corresponds to the number of samples in the table of core data alignment settings, the number of columns corresponds to the number of measurements of geophysical surveys of wells in depth, while on each row of the matrix values are determined only for elements within the possible intervals of shifts relative to the initial position, for which the values of elements on the first line is filled with zeros, because the first sample always corresponds to the beginning of the sampling interval - a fictitious sample, the values on the following lines are determined based on the values on the previous lines, for this, for each possible position of the sample, the values of the deviations of the reservoir properties according to the core and geophysical studies of the wells for the current position of the sample are calculated, multiplied by the value of the corresponding weight coefficient of the sample and determine the position of the sample at the previous level, giving the minimum amount of deviations, taking into account the limited the distance between the samples specified in the settings table and the length of the sampling interval, using auxiliary matrices of a similar structure, which record the possible positions of the first sample of the current sampling interval in the deviation matrix and the position of the sample at the previous level for all subsequent rows, after which determine the position of the last core sample from the adjustment settings table with the minimum value of the sum of deviations, and determine the depth by the found position, then determine the position of the sample on the previous line using the data of the auxiliary matrix, respectively, determine the depths of all the samples under consideration, ensuring the minimum discrepancy between the values of the filtration-capacitive properties for core and geophysical studies of wells. 2. The method according to p. 1, characterized in that in the absence of a part of the data of reservoir properties according to geophysical surveys of wells, the weighted amounts of deviations are compared taking into account the number of samples to be summarized, for this an additional auxiliary matrix is used, in which the number of samples included in calculation of the sum of deviations of the values of the reservoir properties according to the core and according to the results of geophysical studies of wells for each position of the sample under consideration.

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