CN-122014237-A - Method for judging bottom interface of two-stack Dan Qianfeng group by using element logging data

Abstract

The invention belongs to the technical field of petroleum and natural gas exploration and development, and in particular relates to a method for judging a dyadic Dan Qianfeng bottom interface by using element logging data, which comprises the following steps of S1, collecting logging while-drilling rock fragments; S2, roughly dividing the bottom interface of the two-fold system Dan Qianfeng group by combining the regional deposition characteristics and the geological design information to define a roughly divided interface, S3, carrying out X-ray fluorescence spectrum scanning on logging while-drilling rock scraps to obtain strontium, copper and barium element data, S4, carrying out data processing, analysis and judgment on the strontium, copper and barium element data, calculating an interface coefficient JM, and S5, correcting the roughly divided interface depth to obtain the bottom interface depth of the two-fold system Dan Qianfeng group. The method for judging the bottom interface of the two-stack Dan Qianfeng group by using the element logging data corrects the error existing in the lithology combination judging method which mainly relies on the naked eyes of technicians to identify the rock fragments, and has the advantages of small error, small data processing amount, high accuracy, low cost, easy operation and wide application range.

Inventors

• CHEN ZHIWEI
• CONG LI
• Kang Tinghe
• Xiao Xiuhao
• ZHUANG ZIJIAN
• LIU ZHENJIANG
• ZHAO XIAOJIAO
• LIU YANG
• ZHENG YANG
• ZHENG LIJUN
• LIANG ZHIGUO
• Tang Qinxi
• TIAN WEIZHI
• MOU SHUAI
• SONG MINGHUI
• WANG QI
• SUN HUAFU
• CHENG JUNSHENG

Assignees

• 中国石油天然气集团有限公司
• 中国石油集团长城钻探工程有限公司

Dates

Publication Date

20260512

Application Date

20241112

Claims (10)

1. 1. The method for judging the bottom interface of the two-stack Dan Qianfeng group by using the element logging data is characterized by comprising the following steps: s1, collecting logging while-drilling rock fragments; S2, roughly dividing a bottom interface of the two-stack Dan Qianfeng group by combining region deposition characteristics and geological design information, and defining a roughly divided interface; S3, performing X-ray fluorescence spectrum scanning on the logging while-drilling rock scraps to obtain element data; S4, performing data processing, analysis and judgment on the element data, and calculating an interface coefficient JM; and S5, correcting the rough division interface depth to obtain the bottom interface depth of the two-stack Dan Qianfeng group.
2. 2. The method for determining a bottom interface of a two-stack Dan Qianfeng set using elemental log data as claimed in claim 1, wherein in step S3, the elemental data is strontium, copper, barium elemental data.
3. 3. The method for determining a bottom interface of a two-stack Dan Qianfeng set by using elemental logging data as claimed in claim 1, wherein in step S3, before performing X-ray fluorescence spectrum scanning on the logging while drilling cuttings, the pseudo cuttings in the logging while drilling cuttings are manually removed.
4. 4. The method for determining a bottom interface of a two-stack Dan Qianfeng set by using elemental logging data as claimed in claim 1, wherein in step S4, the calculation formula of the interface coefficient JM is: JM= Sr 2 /Cu/Ba-X (1) The method comprises the steps of JM being an interface coefficient, sr being the mass percent of strontium element measured by element logging, cu being the mass percent of copper element measured by element logging, ba being the mass percent of barium element measured by element logging, and X being a correction coefficient.
5. 5. The method for determining a bottom interface of a two-stack Dan Qianfeng set using elemental log data as defined in claim 4, wherein the correction factor X is in the range of 0.65-0.95.
6. 6. The method for determining a bottom interface of a two-stack Dan Qianfeng set using elemental log data as defined in claim 4, wherein the correction factor X is in the range of 0.7-0.9.
7. 7. The method of determining a bottom interface of a two-stack Dan Qianfeng set using elemental log data as defined in claim 4 wherein the interface coefficients and correction coefficients are dimensionless.
8. 8. The method for determining a bottom interface of a two-fold system Dan Qianfeng set using elemental log data as claimed in claim 1, wherein in step S4, the elemental data is processed to amplify the features.
9. 9. The method for determining a bottom interface of a two-fold system Dan Qianfeng set by using elemental logging data according to claim 1, wherein in step S5, the depth of the bottom interface of the two-fold system Dan Qianfeng set is divided twice in combination with the rough-division interface defined in step S2.
10. 10. The method for determining a bottom interface of a two-stack Dan Qianfeng set by using elemental logging data as claimed in claim 9, wherein in step S5, after the secondary division, a depth of abrupt decrease of the interface coefficient JM near the rough division interface from positive to negative is taken as a bottom interface depth of the two-stack Dan Qianfeng set.

Description

Method for judging bottom interface of two-stack Dan Qianfeng group by using element logging data Technical Field The invention belongs to the technical field of petroleum and natural gas exploration and development, and particularly relates to a method for judging a bottom interface of a two-stack Dan Qianfeng group by using element logging data. Background The Dan Qianfeng group is the uppermost group of the two-fold system, the main lithology is a set of purplish red rock stratum with river phase, including siltstone, mudstone, small amount of conglomerate, coarse-to-medium-fine grain clean sandstone and miscellaneous sandstone, and contains plant fossil, namely Taiyuan with sheep teeth, cuspid blades and Korean feather sheep teeth, and is in integrated contact relationship with the group of the box with the underlying upper stone, and the thickness is more than 150m, so that the plant fossil is widely developed in the midwest region of China. In the construction process of on-site drilling, the Dan Qianfeng groups of bottom interfaces are timely and accurately identified to facilitate on-site stratum comparison, predict stratum lithology, judge the drilled horizon and have important significance in restoring paleogeographic paleolithofacies paleoclimate. The conventional method for judging the interface along with the thousand peaks of the diamond mainly comprises a lithology combination judging method, a logging curve identifying method and an element combination identifying method. The lithology combination judging method has the technical problems that due to the improvement of the drilling process, in particular to popularization and application of the PDC bit turbine drilling tool combination, gas drilling and other processes, well logging cuttings are very finely crushed and mixed, and the lithology combination judging method for identifying the cuttings by naked eyes of technicians has larger error. The logging curve identification method can accurately judge the stratum interface, but logging is mostly performed after drilling, and logging is mostly not performed in the drilling process, so that the stratum interface cannot be accurately identified in time. The existing element combination recognition method mainly takes element combination characteristics as the assistance of lithology combination judgment method, and the main method is ① curve anomaly combination method, namely that at the interfaces of different times of stratum, the background value of common combination elements can have obvious mutation at the interfaces, and the characteristic is that the background value has integral mutation. ② The lithology combination method is characterized in that the sediment sources and the sediment backgrounds of the lithology combination method are different from each other, so that the lithology combination is obviously changed due to the different phase environments, the lithology combination is obviously changed due to the different lithology combinations, the element content combination is obviously changed, and the characteristics are particularly obvious at lithology combination conversion interfaces. ③ The characteristic element method is that a certain element is at a key stratum interface, and the reaction is relatively sensitive for a certain reason, so that the stratum interface can be defined according to a certain characteristic element, and element curves have relatively obvious changes at stratum boundaries. Chinese patent CN107313770A discloses a new method for carrying out stratum division by utilizing element logging characteristic sections, which comprises the steps of firstly establishing element logging characteristic sections, summarizing element characteristics of different stratum units and mark layers through the characteristic sections, and carrying out stratum division, wherein the process of establishing the element logging characteristic sections can be divided into seven steps, namely (1) recognizing geological background, (2) carrying out data processing and correction, (3) carrying out element intersection analysis, (4) screening sensitive elements, (5) correcting theoretical values and standard rock samples, (6) carrying out sectional lithology feature extraction, and (7) establishing characteristic sections by partition blocks. The method extracts the sensitive elements through the element intersection graph method, processes 136 intersection graphs, and has larger data processing capacity. Disclosure of Invention Aiming at the technical problems that the error is large when the existing lithology combination judging method relies on the naked eyes of technicians to identify rock fragments, the technical problems that the existing logging curve identifying method can accurately judge logging stratum interfaces but cannot accurately identify logging-free stratum interfaces in the drilling process in time, and the technical problems that the existing element combi