A combined method for gas-bearing layer identification in a complex sandstone reservoir

Langgu Depression is a mature oil and gas exploration area with complicated lithological and physical properties. The varying formation fluid, low-resistivity hydrocarbon-bearing reservoirs, and non-uniform logging series greatly increase the difficulty of gas reservoir identification. The Monte Carlo method is employed to simulate the neutron–gamma logging responses to gas saturation and the influential factors. According to the result, a new gas identification chart eliminating the influence of porosity and formation water salinity is proposed to identify gas reservoirs in the old wells. At the same time, a fluid factor extracted from array acoustic logging and core measurement data is sensitive to the development of gas-bearing layers and useful for the identification of gas reservoirs in the new wells with array acoustic logging. The field examples show that the new combined method greatly improves the ability to identify gas-bearing layers and works well in old well reexamination and new well interpretation

PyPose v0.6: The Imperative Programming Interface for Robotics

PyPose is an open-source library for robot learning. It combines a learning-based approach with physics-based optimization, which enables seamless end-to-end robot learning. It has been used in many tasks due to its meticulously designed application programming interface (API) and efficient implementation. From its initial launch in early 2022, PyPose has experienced significant enhancements, incorporating a wide variety of new features into its platform. To satisfy the growing demand for understanding and utilizing the library and reduce the learning curve of new users, we present the fundamental design principle of the imperative programming interface, and showcase the flexible usage of diverse functionalities and modules using an extremely simple Dubins car example. We also demonstrate that the PyPose can be easily used to navigate a real quadruped robot with a few lines of code

Simulation Research on Application of Azimuth Electromagnetic Wave in Coal Seam Detection

Aiming at the problems of poor detection accuracy and low efficiency on the roof and floor interface in horizontal well drilling in coal mine, the design idea of explosion-proof azimuth-while-drilling electromagnetic wave logging instrument in coal mine was put forward. In order to suit the working environment of underground coal seam, the change law of the influence of instrument parameters such as source distance and coil installation angle on the signal response was obtained through forward simulation. Through the simulation research on the response of azimuth-while-drilling electromagnetic wave logging instrument, it provided a basis for selection of parameter optimization design of the instruments applicable to the underground coal mine, and the change law of the response of coal rock roof and floor interface was mastered. The application of this instrument will improve the detection accuracy and efficiency on the roof and floor

Automatic demarcation of sequence stratigraphy using the method of well logging multiscale data fusion

Strata division with well logging utilizes the abrupt changing points or regions of signals, while the changing law of the wavelet modulus maxima under different scales can exactly describe the position and modality of the changing points. Based on the idea of reconstruction of wavelet modulus maxima, the well logging data fusion method built on the multiscale edge detection principle is put forward and is applied to the quantitative demarcation of sequence stratigraphy. For case study, single logging curve and multiscale fusion curve in well A in Shengtuo Oilfield are processed by quadric spline wavelet and thereby sequence boundaries on different scales can be detected. The result shows: by demarcating sequence stratigraphic units with the multiscale fusion curve analysis, better effect could be obtained. The energy accumulation and distribution on the wavelet time-frequency graph could clearly reflect the boundaries and cycle types of parasequences and parasequence sets. All these researches provide a completely new method for the quantitative demarcation of sequence and its inner depositional features. Key words: logging curve, wavelet transform, multiscale, data fusion, sequence stratigraph