Review on the progress for physical simulation for gas reservoirs co-production in multi-pressure system

The gas reservoirs co-production in multi-pressure system is one of the important measures to improve the development efficiency of the superposed gas-bearing systems. However, the co-production effect is not ideal due to the special reservoir forming background. The mechanism of co-production and high-efficient development of the multi-pressure system has become an key scientific problem, which restricts the efficient exploration and development of superposed gas-bearing systems. This paper focuses on the gas reservoirs co-production in multi-pressure system, and divides the physical simulation types of co-production into two separate fields: coalbed methane and non coalbed methane. It clarifies the current research status of gas reservoirs co-production in multi-pressure system from the aspects of device functions and characteristics, understanding of co-production, and existing problems. Firstly, the large-scale physical simulation test device can effectively eliminate or weaken the problems of homogeneous single-type reservoir samples, single monitoring data means and single stress loading form caused by paralleling multiple core grippers to build the physical simulation model. The development direction of the physical simulation for co-production in multi-pressure system should be to achieve true three-dimensional heterogeneous complex in-situ stress state of large-scale heterogeneous multi-type reservoir samples. The characteristics of fluid pressure transmission between adjacent reservoirs, the inter-layer crossflow, the multi-phase natural gas symbiosis should be considered. On this basis, the sensitivity of co-production of multi-pressure system to reservoir physical properties was deeply summarized. The differences in inter-layer pressure difference, permeability, effective stress, water saturation and other factors may induce the fluid interference and reservoir gas production damage, and optimizing co-production style may be a way to reduce the fluid interference and reservoir gas production damage. In totally, the next research should focus on exploring the influence of the coupling effect of low porosity and low permeability, gas water two-phase flow, multiphase gas symbiosis and coexistence of multiple types of reservoirs on the dynamic evolution law of reservoir-wellbore flow field induced by co-production fluid interference, clarifying the reservoir damage and its mechanism of different phase fluid intrusions on the reservoir, and revealing the coupling flow characteristics of inter-layer crossflow and wellbore pipe flow considering the fluid interference effect

Deformation and failure characteristics of gas drainage drilling-reaming coal mass in non-uniform stress field

The deformation and failure characteristics of coal around gas drainage boreholes in deep soft and low permeability coal seams affect coal seam gas pre-drainage. Based on the condition of non-uniform stress field, the mechanical model of borehole disturbed coal mass was developed, the analytical solutions of stress, strain and displacement in the damaged zone, plastic zone and elastic zone of borehole disturbed coal mass were deduced, the influence law of factors such as lateral pressure coefficient, load condition, cohesion and hole expanding behavior on the “three zone” distribution of disturbed coal mass were analyzed, and the reliability of the theoretical model was verified through engineering examples. The results show that under the condition of non-uniform stress field, the plastic zone and damaged zone of disturbed coal mass are elliptical distribution. With the increase of lateral pressure coefficient, the length of the upper and lower wings of the plastic zone and damaged zone of disturbed coal mass becomes larger and larger, and the radius of the plastic zone and damaged zone in the direction of smaller stress is greater than the radius of the two zones in the direction of large stress. The radius of plastic zone and damaged zone of coal mass increases with the increase of vertical load, and decreases with the increase of initial cohesion and residual cohesion. The influence of vertical load on its shape can be ignored. When the borehole diameter is expanded from 0.1 m to 0.5 m, the coal mass 0−1.0 m away from the borehole center produces a strong disturbance, the coal mass 1.0−4.6 m produces a weak disturbance, and the coal mass after 4.6 m has almost no influence. Through the field example of No.16032 bottom pumping roadway hydraulic reaming in the Guhanshan coal mine, it is observed that the disturbed coal mass in the reaming section has a high degree of damage. Based on the coal output, the reaming diameter is deduced to be 1.5 m, and then the deformation and damage characteristics of drilling reaming coal mass are obtained through theoretical calculation and numerical simulation respectively. The two are in good agreement, so as to verify the reliability of the theoretical model

CRISPR/Cas9 Screen Uncovers Functional Translation of Cryptic lncRNA-Encoded Open Reading Frames in Human Cancer

Emerging evidence suggests that cryptic translation within long noncoding RNAs (lncRNAs) may produce novel proteins with important developmental/physiological functions. However, the role of this cryptic translation in complex diseases (e.g., cancer) remains elusive. Here, we applied an integrative strategy combining ribosome profiling and CRISPR/Cas9 screening with large-scale analysis of molecular/clinical data for breast cancer (BC) and identified estrogen receptor α-positive (ER+) BC dependency on the cryptic ORFs encoded by lncRNA genes that were upregulated in luminal tumors. We confirmed the in vivo tumor-promoting function of an unannotated protein, GATA3-interacting cryptic protein (GT3-INCP) encoded by LINC00992, the expression of which was associated with poor prognosis in luminal tumors. GTE-INCP was upregulated by estrogen/ER and regulated estrogen-dependent cell growth. Mechanistically, GT3-INCP interacted with GATA3, a master transcription factor key to mammary gland development/BC cell proliferation, and coregulated a gene expression program that involved many BC susceptibility/risk genes and impacted estrogen response/cell proliferation. GT3-INCP/GATA3 bound to common cis regulatory elements and upregulated the expression of the tumor-promoting and estrogen-regulated BC susceptibility/risk genes MYB and PDZK1. Our study indicates that cryptic lncRNA-encoded proteins can be an important integrated component of the master transcriptional regulatory network driving aberrant transcription in cancer, and suggests that the hidden lncRNA-encoded proteome might be a new space for therapeutic target discovery

Bone Metastasis Initiation Is Coupled with Bone Remodeling through Osteogenic Differentiation of NG2+ Cells

The bone microenvironment is dynamic and undergoes remodeling in normal and pathologic conditions. Whether such remodeling affects disseminated tumor cells (DTC) and bone metastasis remains poorly understood. Here, we demonstrated that pathologic fractures increase metastatic colonization around the injury. NG2+ cells are a common participant in bone metastasis initiation and bone remodeling in both homeostatic and fractured conditions. NG2+ bone mesenchymal stem/stromal cells (BMSC) often colocalize with DTCs in the perivascular niche. Both DTCs and NG2+ BMSCs are recruited to remodeling sites. Ablation of NG2+ lineage impaired bone remodeling and concurrently diminished metastatic colonization. In cocultures, NG2+ BMSCs, especially when undergoing osteodifferentiation, enhanced cancer cell proliferation and migration. Knockout of N-cadherin in NG2+ cells abolished these effects in vitro and phenocopied NG2+ lineage depletion in vivo. These findings uncover dual roles of NG2+ cells in metastasis and remodeling and indicate that osteodifferentiation of BMSCs promotes metastasis initiation via N-cadherin-mediated cell-cell interaction. SIGNIFICANCE: The bone colonization of cancer cells occurs in an environment that undergoes constant remodeling. Our study provides mechanistic insights into how bone homeostasis and pathologic repair lead to the outgrowth of disseminated cancer cells, thereby opening new directions for further etiologic and epidemiologic studies of tumor recurrences. This article is highlighted in the In This Issue feature, p. 247

The Adaptive Streaming SAR Back-Projection Algorithm Based on Half-Precision in GPU

The back-projection (BP) algorithm is completely accurate in the imaging principle, but the computational complexity is extremely high. The single-precision arithmetic used in the traditional graphics processing unit (GPU) acceleration scheme has low throughput and its usage of the video memory is large. An adaptive asynchronous streaming scheme for the BP algorithm based on half-precision is proposed in this study, and then it is extended to the fast back-projection (FBP) algorithm. In this scheme, the adaptive loss factors selection strategy ensures the dynamic range of data, the asynchronous streaming structure ensures the efficiency of large scene imaging, and the mixed-precision data processing ensures the imaging quality. The schemes proposed in this paper are compared with BP, FBP, and fast factorized back-projection (FFBP) algorithms of single-precision in GPU. The experimental results show that the two half-precision acceleration schemes in this paper reduce the video memory usage to 74% and 59% of the single-precision schemes with guaranteed image quality. The efficiency improvements of the proposed schemes are almost one and 0.5 times greater than that of the corresponding single-precision scheme, and the advantage can be more obvious when dealing with large computations

A Novel Error Correction Method for Airborne HRWS SAR Based on Azimuth-Variant Attitude and Range-Variant Doppler Domain Pattern

In high-resolution and wide-swath (HRWS) synthetic aperture radar (SAR) imaging, the azimuth multi-channel technique effectively suppresses azimuth ambiguity, serving as a reliable approach for achieving wide-swath imaging. However, due to mechanical vibrations of the platform and airflow instabilities, airborne SAR may experience errors in attitude and flight path during operation. Furthermore, errors also exist in the antenna patterns, frequency stability, and phase noise among the azimuth multi-channels. The presence of these errors can cause azimuth multi-channel reconstruction failure, resulting in azimuth ambiguity and significantly degrading the quality of HRWS images. This article presents a novel error correction method for airborne HRWS SAR based on azimuth-variant attitude and range-variant Doppler domain pattern, which simultaneously considers the effects of various errors, including channel attitude errors and Doppler domain antenna pattern errors, on azimuth reconstruction. Attitude errors are the primary cause of azimuth-variant errors between channels. This article uses the vector method and attitude transformation matrix to calculate and compensate for the attitude errors of azimuth multi-channels, and employs the two-dimensional frequency-domain echo interferometry method to calculate the fixed delay errors and fixed phase errors. To better achieve channel error compensation, this scheme also considers the estimation and compensation of Doppler domain antenna pattern errors in wide-swath scenes. Finally, the effectiveness of the proposed scheme is confirmed through simulations and processing of airborne real data