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After more than 20 years of development, the exploration and production of multi-bed coalbed methane in western Guizhou is now in a key growth phase. Based on geological characteristics of CBM and requirements of main development engineering in this area, we have looked into suitable fracturing and drainage modes for this area. This study shows that the Liupanshui coalfield has a high stress field, so staged fracturing with large discharge and high volume of fracturing fluid and sand and increase of the used quantity of high strength ceramic beads is effective for this kind of multi-bed coal reservoir. In contrast, Zhina coalfield has a relatively low stress field, and the Qianbei coalfield has transitional stress conditions. Separate layer fracturing by sleeve diverter in the Zhijin block ensures effective fracturing of multi-production layers. This method enhances fracturing efficiency and decreases fracturing cost and is therefore recommended for the whole area. Coiled tubing fracturing widely used in other countries is recommended for the Zhina and Qianbei coalfields. Commingled drainage and production is considered the best choice for the development of multi-bed CBM reservoirs. The basic geologic conditions for commingled drainage production of multiple layers are that the main productive layers can be ensured to produce gas preferentially and smoothly and the critical desorption pressure liquid level of other productive layers are above the roof depth of the main productive layers. On this basis, all the layers can be produced in an orderly manner by regulating the casing pressure and liquid level depth in different draining phases. [ABSTRACT FROM AUTHOR]

[Objective]The paper provided a reference for establishment of effective prevention mechanism against aphids in Zhenyuan tobacco area. [Method] The initial population quantity of aphids in early spring, migration of winged aphids, occurrence regularity and damage status of Myzus persicae and aphid-transmitted virus (PVY + CMV) were investigated in Zhenyuan County from 2014 to 2015 using 10-point checkerboard sampling method, yellow dish trapping method and 5-point sampling method. [Result] The total amount of aphids in Brassica campestrii was the largest among overwintering hosts, with an average of 18.44 specimen/plant. The migration of winged aphids presented bimodal pattern; the population dynamics of wingless aphids presented unimodal pattern, and the occurrence peak was from May to June. [Conclusion] Field control against M. persicae in tobacco fields should be conducted from mid May to early June. [ABSTRACT FROM AUTHOR]