While-drilling electromagnetic wave logging cross-dimensional simulation method suitable for 2D stratum model

Abstract

The invention discloses a while-drilling electromagnetic wave logging cross-dimensional simulation method suitable for a 2D model. The method comprises the following steps: s1, inputting instrument parameters, a stratum model and other information; s2, determining a while-drilling electromagnetic wave logging forward modeling calculation domain; s3, performing variable-scale sliding windowing processing on the model; s4, calculating a model complexity factor; s5, judging whether the complexity factor of the model is greater than a threshold value or not: if so, executing a step s6, otherwise, executing a step s9; s6, carrying out dimension reduction rationality analysis on a simulation result, and calculating a model quality control factor; s7, judging whether the model quality control factor is greater than a threshold value or not, if so, executing a step s8, otherwise, executing a step s9; s8, calculating an original 2D stratum model response by adopting a 2.5 D algorithm; s9, solving the simplified 1D stratum model response by adopting an analytical solution to obtain a simulation result. According to the method, the optimal algorithm can be adaptively selected according to the stratum model to realize quick and accurate forward modeling of the electromagnetic wave logging while drilling of the 2D stratum model.

Description

technical field [0001] The invention relates to the field of petroleum exploration and development, in particular to an electrical logging method, and more specifically to an electromagnetic wave logging while drilling cross-dimensional simulation method suitable for a 2D formation model. Background technique [0002] Because of its large detection depth and sensitivity to formation resistivity, electromagnetic logging while drilling has been widely used in real-time geosteering of highly deviated wells / horizontal wells and fine evaluation of reservoirs. However, due to the influence of factors such as surrounding rock and well deviation, the response of electromagnetic logging while drilling is complex. Therefore, a set of fast forward modeling methods are required for pre-drilling forward modeling, real-time inversion and post-drilling evaluation of electromagnetic logging while drilling. [0003] At present, in order to meet the needs of real-time data processing of elect...

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Problems solved by technology

However, so far, there is still a contradiction between the speed of LWD simulation and the complexity of the model. Specifically: (1) The formation model is simplified to 1D, and the analytical method is used to solve it, and the simulation speed is fast. However, when the stratum structure is complex, the simulation accuracy is low; (2) When the 2D stratum model is used, the stratum structure can be simulated well and an accurate response can be obtained, but the simulation speed is slow and it is difficult to meet the needs of real-time data processing

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