Search

The productivity equation of a gas well is, in the final analysis, an expression that describes the relationship between the production of a gas well and its bottom-hole flowing pressure. There are two kinds of productivity equations in common use at present: binomial productivity equation and exponential productivity equation. Combined with the modified isochronal well test, the test data are interpreted, and it is found that the open flow rates calculated by the two productivity equations are basically the same when the pressure difference at the test point is large, and the deviation of the exponential productivity equation is large when the pressure difference at the test point is small. Using binomial productivity equation and modifying isochronous well test, we established the single-point deliverability formula for the Jingbian sector of the Yan’an gas field. The field experience formula and production data are used to verify it. Their average errors are 2.59% and 7.12%, respectively; and the coincidence rate of productivity evaluation is 90%. The one-point productivity formula established has high precision and is suitable for productivity analysis of gas wells in paleozoic reservoirs in the Jingbian sector of the Yan’an gas field. This paper provides insights into the one-point productivity evaluation and its future application in the gas field.

Information on interwell connectivity is important in reservoir field dynamic analysis. However, all conventional methods, such as the tracer test, interference well test, and numerical simulation, have disadvantages. These disadvantages include the length of time taken, high costs, and the effect on oilfield production. Thus, research focus has been directed toward the development of approaches that use production and injection data to obtain interwell connectivity data. Prevailing interwell connectivity models are sensitive to shut-ins, and their corresponding inversion methods are unreliable. The improved interwell connectivity model presented in this study exhibits enhanced robustness to shut-ins. The application of seepage theories and numerical simulation methods enables the main model parameters to absorb prior geological knowledge to characterize the reservoir and improve the initial estimate of connectivity. Corresponding inverse methods for model parameters are implemented based on Bayesian inverse theory and the projection gradient method and obtain greater robustness for the model parameter, compared with those in previous studies. Testing of a heterogeneous synthetic reservoir and a Z16 reservoir block demonstrates that the methodology can precisely determine the interwell connectivity and can be used in real oilfields. [ABSTRACT FROM AUTHOR]

Circadian rhythm is an internal regulatory mechanism formed in organisms in response to the circadian periodicity in the environment, which modulates the pathophysiological events, occurrence and development of diseases, and the response to treatment in mammals. It significantly influences the susceptibility, injury, and recovery of ischemic stroke, and the response to therapy. Accumulating evidence indicates that circadian rhythms not only regulate the important physiological factors of ischemic stroke events, such as blood pressure and coagulation-fibrinolysis system, but also participate in the immuno-inflammatory reaction mediated by glial cells and peripheral immune cells after ischemic injury and the regulation of neurovascular unit(NVU). This article aims to link molecular, cellular, and physiological pathways in circadian biology to the clinical consequences of ischemic stroke and to illustrate the impact of circadian rhythms on ischemic stroke pathogenesis, the regulation of NVU, and the immuno-inflammatory responses. The regulation of circadian rhythm by traditional Chinese medicine is reviewed, and the research progress of traditional Chinese medicine intervention in circadian rhythm is summarized to provide a reasonable and valuable reference for the follow-up traditional Chinese medicine research and molecular mechanism research of circadian rhythm.

Objective: To study the effects of Compound Danshen Tablet (CDT) on the expression of the beta-amyloid peptide (Abeta) in transgenic cell model of Alzheimer's disease (AD)., Methods: The previously successfully cultured transgenic cell model was used as AD transgenic cell model. Rats were fed with 0.5, 1, 2, and 4 times CDT. The AD transgenic cells were cultured in 0.5, 1, 2, and 4 times rats' sera. The expressions of Abeta in transgenic cells were detected using Western blot., Results: The optimal dose effect was obtained in the 1 time CDT group at 24 h., Conclusion: CDT could reduce the Abeta expression level in the AD transgenic cell model.

In this paper, the theoretical and experimental researches concerning the prevention and treatment of myocardial ischemia/reperfusion (I/R) injury by Chinese medicine (CM) therapy of activating blood circulation and removing stasis in recent five years were reviewed, and the mechanisms were summarized. Thereby, based upon the current development of molecular biology and application of new technology, the authors offered their suggestions on the emphasized points and methods of present CM study in this scope.