Sandstone reservoir fluid property rapid interpretation method based on development well logging gas logging data

Abstract

The present application relates to the technical field of drilling, in particular to a sandstone reservoir fluid property rapid interpretation method based on development well logging gas logging data. The method comprises obtaining development well logging data, including total hydrocarbon parameter Tg, methane parameter C1 and heavy hydrocarbon parameter C2+; determining reservoir well section according to total hydrocarbon parameter Tg, methane parameter C1 and heavy hydrocarbon parameter C2+; calculating heavy hydrocarbon contribution coefficient ZS and total hydrocarbon contribution coefficient TS according to total hydrocarbon parameter Tg, methane parameter C1 and heavy hydrocarbon parameter C2+; drawing data points to total hydrocarbon contribution coefficient TS-heavy hydrocarbon contribution coefficient ZS chart according to regional statistics of oil layer, water layer and dry layer data confirmed by oil testing; placing data points in total hydrocarbon contribution coefficient TS-heavy hydrocarbon contribution coefficient ZS chart and outputting interpretation results, wherein the region where the data points are located is the corresponding fluid interpretation and evaluation result. The method can quickly realize semi-quantitative interpretation of block reservoir fluid property and effectively overcome technical problems caused by conventional geology in rapid drilling.

Description

Technical Field

[0001] This invention relates to the field of drilling technology, and specifically to a rapid interpretation method for fluid properties of sandstone reservoirs based on well logging gas logging data from development wells. Background Technology

[0002] The PLS-II logging tool is a logging instrument for rapid identification of oil and gas shows. Its chromatographic detection uses infrared gas detection, based on the principle that different molecules selectively absorb infrared radiation of different wavelengths. Recording the absorption of infrared light by molecules yields an infrared spectrum. Its measured parameters include methane parameter C1, heavy hydrocarbon parameter C2+, and the total hydrocarbon parameter Tg, which is the algebraic sum of methane parameter C1 and heavy hydrocarbon parameter C2+.

[0003] Traditional logging gas logging interpretation and evaluation charts are based on the ratio relationship between C1 and nC5. However, the PLS-II logging chromatograph can only analyze the methane parameter C1 and the heavy hydrocarbon parameter C2+. Therefore, establishing a gas logging interpretation and evaluation chart for PLS-II logging chromatographic data in development wells is very important in the logging interpretation and evaluation system, and it fills a gap in the interpretation and evaluation system of this type of chromatograph. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a rapid interpretation method for the fluid properties of sandstone reservoirs based on well logging and gas logging data from development wells. This method can quickly achieve a semi-quantitative interpretation of the fluid properties of reservoirs in a block, effectively solving the technical challenges posed by rapid drilling to conventional geology.

[0005] This invention discloses a rapid interpretation method for fluid properties in sandstone reservoirs based on well logging gas logging data. The technical solution includes:

[0006] Obtain logging data from development wells, including total hydrocarbon parameter Tg, methane parameter C1, and heavy hydrocarbon parameter C2+;

[0007] The reservoir interval is determined based on the total hydrocarbon parameter Tg, methane parameter C1, and heavy hydrocarbon parameter C2+.

[0008] The heavy hydrocarbon contribution coefficient ZS and the total hydrocarbon contribution coefficient TS are calculated based on the total hydrocarbon parameter Tg, the methane parameter C1 and the heavy hydrocarbon parameter C2+.

[0009] Statistics on oil, water, and dry reservoir data verified by oil testing were compiled by region, and the data points were plotted on the total hydrocarbon contribution coefficient TS-heavy hydrocarbon contribution coefficient ZS chart.

[0010] Place the data points in the total hydrocarbon contribution coefficient TS-heavy hydrocarbon contribution coefficient ZS chart and output the interpretation results. The region where the data points are located represents the corresponding fluid interpretation and evaluation results.

[0011] Preferably, determining the reservoir interval based on the total hydrocarbon parameter Tg, methane parameter C1, and heavy hydrocarbon parameter C2+ includes:

[0012] Select sandstone well sections with gas logging anomalies in total hydrocarbon parameter Tg, methane parameter C1, and heavy hydrocarbon parameter C2+. Select a specified distance range above the sandstone layer for total hydrocarbon parameter Tg, methane parameter C1, and heavy hydrocarbon parameter C2+, and calculate the average values ​​as the base values ​​for total hydrocarbon parameter Tg, methane parameter C1, and heavy hydrocarbon parameter C2+.

[0013] Take the maximum effective values ​​of total hydrocarbon parameter Tg anomalies, methane parameter C1 anomalies, and heavy hydrocarbon parameter C2+ anomalies in the sandstone well section, and remove data affected by single connection and tripping in / out;

[0014] Abnormal well sections with gas measurement values ​​greater than or equal to 2.0 times the baseline value and sandstone layer thickness greater than or equal to 0.5m were selected as reservoir well sections.

[0015] Preferably, the calculation of the heavy hydrocarbon contribution coefficient ZS includes:

[0016] Calculate the light hydrocarbon increase coefficient C1S = (C1 outlier - C1 base value) / C1 base value;

[0017] Calculate the heavy hydrocarbon increase coefficient CnS = (C2 + outlier - C2 + base value) / C2 + base value;

[0018] Calculate the contribution coefficient of heavy hydrocarbons ZS = CnS / C1S.

[0019] Preferably, the calculation of the total hydrocarbon contribution factor TS includes:

[0020] Calculate the total hydrocarbon contribution coefficient TS = total hydrocarbon change / total hydrocarbon base value.

[0021] Preferably, the total hydrocarbon contribution coefficient TS-heavy hydrocarbon contribution coefficient ZS map is divided into three regions: oil layer, water layer, and dry layer.

[0022] Preferably, the specified distance range is 5m to 10m above the sandstone layer.

[0023] The beneficial effects of this invention are as follows: This invention utilizes the heavy hydrocarbon contribution coefficient (ZS) and the total hydrocarbon contribution coefficient (TS) to reflect the hydrocarbon-bearing properties of the reservoir; it employs the cross-interpretation method of the total hydrocarbon contribution coefficient (TS) and the heavy hydrocarbon contribution coefficient (ZS) to identify and evaluate the fluid properties of gas-shown layers; it statistically analyzes oil, water, and dry layer data verified by oil testing by region, plots the data points on a TS-ZS total hydrocarbon contribution coefficient chart, and divides the chart into three regions—oil, water, and dry—based on data statistical principles to characterize the interpretation and evaluation results. This invention has been applied to more than 20 wells in the Jianghan Oilfield, achieving a single-item accuracy rate of over 85% in identifying and evaluating oil, water, and dry layers, with an overall accuracy rate approaching 90%, demonstrating excellent application results. It solves the technical problem of reservoir logging identification and rapid evaluation in oilfield development wells and provides a valuable reference for establishing fluid interpretation and evaluation methods for sandstone reservoirs in other blocks in the future. Attached Figure Description

[0024] Figure 1 This is a schematic diagram illustrating the working principle of the present invention;

[0025] Figure 2 This is a schematic diagram of the identification and evaluation chart drawn from data points used in this invention;

[0026] Figure 3 This is the first embodiment of the application of the present invention;

[0027] Figure 4 This is a second embodiment of the application of the present invention. Detailed Implementation

[0028] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0029] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0030] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0031] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0032] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0033] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0034] References to "one embodiment" or "some embodiments" in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized. "A plurality" means "two or more."

[0035] Figure 1 The diagram illustrates a preferred embodiment of a rapid interpretation method for sandstone reservoir fluid properties based on well logging gas logging data provided in this application. For ease of explanation, only the parts relevant to this embodiment are shown, and are detailed below:

[0036] This invention utilizes the values ​​of total hydrocarbon parameter Tg, methane parameter C1, and heavy hydrocarbon parameter C2+ measured by a well logging instrument in a development well. It calculates the heavy hydrocarbon amplification coefficient CnS = (C2+ outlier - C2+ baseline) / C2+ baseline and the light hydrocarbon amplification coefficient C1S = (C1 outlier - C1 baseline) / C1 baseline; then it calculates the heavy hydrocarbon contribution coefficient ZS = CnS / C1S. Based on the gas logging characteristic that higher reservoir energy corresponds to a greater increase in total hydrocarbons, the oil-bearing potential of the reservoir is judged by the magnitude of the total hydrocarbon growth. The higher the total hydrocarbon contribution, the better the oil-bearing potential of the reservoir. The total hydrocarbon contribution coefficient TS = total hydrocarbon change / total hydrocarbon baseline value.

[0037] Traditional well logging interpretation and evaluation charts are basically based on the ratio relationship between C1 and nC5. However, the PLS-II development well logging tool can only analyze the total hydrocarbon parameter Tg, methane parameter C1, and heavy hydrocarbon parameter C2+. It collects and records the values ​​of the total hydrocarbon parameter Tg, methane parameter C1, and heavy hydrocarbon parameter C2+ in % dimension. The collection and recording step size is usually 1 point / m. By establishing interpretation charts, it can quickly achieve semi-quantitative interpretation of reservoir fluid properties.

[0038] The identification and specific evaluation steps are as follows:

[0039] 1) Collect and record total hydrocarbon parameters (Tg), methane parameters (C1), and heavy hydrocarbon parameters (C2+) using a well logging instrument;

[0040] 2) Select sandstone well sections with gas logging anomalies in total hydrocarbon parameter Tg, methane parameter C1, and heavy hydrocarbon parameter C2+. Select the total hydrocarbon parameter Tg, methane parameter C1, and heavy hydrocarbon parameter C2+ 5m to 10m above the sandstone layer and calculate the average value as the base value.

[0041] 3) Take the maximum effective values ​​of total hydrocarbon anomalies, methane C1 anomalies, and heavy hydrocarbon C2+ anomalies in the sandstone well section, and remove data affected by single connection and tripping.

[0042] 4) Select abnormal well sections with gas measurement values ​​greater than or equal to 2.0 times the base value and sandstone layer thickness greater than or equal to 0.5m as reservoir sections.

[0043] 5) Calculate the light hydrocarbon amplification coefficient C1S = (C1 outlier - C1 base value) / C1 base value; the heavy hydrocarbon amplification coefficient CnS = (C2 + outlier - C2 + base value) / C2 + base value; the heavy hydrocarbon contribution coefficient ZS = CnS / C1S;

[0044] 6) Based on the gas measurement characteristic that the higher the reservoir energy, the greater the increase in total hydrocarbons, the oil content of the reservoir is judged by the increase in total hydrocarbons. The higher the contribution of total hydrocarbons, the better the oil content of the reservoir. The total hydrocarbon contribution coefficient TS = change in total hydrocarbons / total hydrocarbon base value is calculated.

[0045] 7) Statistically analyze the data of oil layers, water layers, and dry layers verified by oil testing, and plot the data points on the total hydrocarbon contribution coefficient (TS) - heavy hydrocarbon contribution coefficient (ZS) chart. Based on the principles of data statistics, determine the boundaries to divide the chart into three regions: oil layer, water layer, and dry layer. Figure 2 As shown in the table below:

[0046]

[0047] 8) Place the data points in the total hydrocarbon contribution coefficient TS-heavy hydrocarbon contribution coefficient ZS chart. The area where the data points are located represents the corresponding fluid interpretation and evaluation results.

[0048] Example 1

[0049] This embodiment uses the present invention in the Qian 3 oilfield of Guanghua Oilfield. 3 The application of well A in the oil group development well will be explained.

[0050] Application of Well A: Stratum: Subsurface 3 3 The oil group contains 9 anomaly zones with a total thickness of 35.5m. These include 2 oil-bearing zones (13.5m thick), 5 dry zones (12.0m thick), and 2 water-bearing zones (5.0m thick). The total hydrocarbon contribution coefficient (THC) for the oil-bearing zone is 12.19-14.35, and for the dry zone it is 1.31-2.76. In the dry zone, the THC contribution coefficient is 0.20-0.76, and for the dry zone it is 0.13-1.64. In the water-bearing zone, the THC contribution coefficient is 1.24-1.28, and for the dry zone it is 0.56-0.71. Based on the evaluation criteria of the TS-ZS chart (total hydrocarbon contribution coefficient - heavy hydrocarbon contribution coefficient), the results conform to the characteristics of oil-bearing, dry, and water-bearing zones. The point selection is good and consistent with well logging interpretation and testing results. Figure 3 As shown.

[0051] Example 2

[0052] This embodiment uses the present invention in the Qian 3 oilfield of Guanghua Oilfield. 3 The application of well B in the oil group development well will be explained.

[0053] Application of Well B: Stratum: Subsurface 3 3 The oil group contains 11 anomaly zones, totaling 30.0m in thickness. These include one oil-bearing zone (5.0m thick), six dry zones (13.0m thick), and four water-bearing zones (12.0m thick). The total hydrocarbon contribution coefficient (THC) for the oil-bearing zone is 1.78, and for the heavy hydrocarbons, it is 1.09. For the dry zones, the THC contribution coefficient ranges from 0.32 to 1.00, and for the heavy hydrocarbons, it ranges from 0.52 to 2.53. For the water-bearing zones, the THC contribution coefficient ranges from 1.66 to 14.55, and for the heavy hydrocarbons, it ranges from 0.27 to 0.60. Based on the evaluation criteria of the TS-ZS chart (total hydrocarbon contribution coefficient - heavy hydrocarbon contribution coefficient), the results conform to the characteristics of oil-bearing, dry, and water-bearing zones. The point selection is good and consistent with well logging interpretation and testing results. Figure 4 As shown.

[0054] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process may be rearranged without departing from the scope of this disclosure. The appended method claims provide elements of various steps in an exemplary order and are not intended to limit the scope to the specific order or hierarchy described.

[0055] The disclosed embodiments have been described above to enable any person skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments without departing from the spirit and scope of this disclosure. Therefore, this disclosure is not limited to the embodiments given herein, but is consistent with the broadest scope of the principles and novel features disclosed in this application.

Claims

1. A rapid interpretation method for fluid properties of sandstone reservoirs based on well logging gas logging data, characterized in that, include: Obtain logging data from development wells, including total hydrocarbon parameter Tg, methane parameter C1, and heavy hydrocarbon parameter C2+; The reservoir interval is determined based on the total hydrocarbon parameter Tg, methane parameter C1, and heavy hydrocarbon parameter C2+. The heavy hydrocarbon contribution coefficient ZS and the total hydrocarbon contribution coefficient TS are calculated based on the total hydrocarbon parameter Tg, the methane parameter C1 and the heavy hydrocarbon parameter C2+. Statistics on oil, water, and dry reservoirs verified by oil testing were compiled by region, and the data points were plotted on the total hydrocarbon contribution coefficient TS-heavy hydrocarbon contribution coefficient ZS chart. Place the data points in the total hydrocarbon contribution coefficient TS-heavy hydrocarbon contribution coefficient ZS chart and output the interpretation results. The area where the data points are located is the corresponding fluid interpretation evaluation result. The calculation of the heavy hydrocarbon contribution coefficient ZS includes: Calculate the light hydrocarbon increase coefficient C1S = (C1 outlier - C1 base value) / C1 base value; Calculate the heavy hydrocarbon increase coefficient CnS = (C2 + outlier - C2 + base value) / C2 + base value; Calculate the heavy hydrocarbon contribution coefficient ZS = CnS / C1S; The determination of reservoir intervals based on total hydrocarbon parameter Tg, methane parameter C1, and heavy hydrocarbon parameter C2+ includes: Select sandstone well sections with gas logging anomalies in total hydrocarbon parameter Tg, methane parameter C1, and heavy hydrocarbon parameter C2+. Select a specified distance range above the sandstone layer for total hydrocarbon parameter Tg, methane parameter C1, and heavy hydrocarbon parameter C2+, and calculate the average values ​​as the base values ​​for total hydrocarbon parameter Tg, methane parameter C1, and heavy hydrocarbon parameter C2+. Take the maximum effective values ​​of total hydrocarbon parameter Tg anomalies, methane parameter C1 anomalies, and heavy hydrocarbon parameter C2+ anomalies in the sandstone well section, and remove data affected by single connection and tripping in / out; Abnormal well sections with gas logging values ​​greater than or equal to 2.0 times the baseline value and sandstone layer thickness greater than or equal to 0.5m were selected as reservoir well sections. The calculation of the total hydrocarbon contribution factor TS includes: Calculate the total hydrocarbon contribution coefficient TS = total hydrocarbon change / total hydrocarbon base value.

2. The rapid interpretation method for sandstone reservoir fluid properties based on well logging gas logging data from development wells according to claim 1, characterized in that, The total hydrocarbon contribution coefficient TS-heavy hydrocarbon contribution coefficient ZS map is divided into three regions: oil layer, water layer, and dry layer.

3. The rapid interpretation method for sandstone reservoir fluid properties based on well logging gas logging data according to claim 1, characterized in that, The specified distance range is 5m to 10m above the sandstone layer.

Images