Geologically controlling factors on coal bed methane （CBM） productivity in Liulin

It is of great significance to forecast high yield of CBM wells and analyze dynamic production by having an overall study on the characteristics of the produced CBM and determining the main factors influencing the productivity of CBM. With the test report and the related geological parameters of a single well, methods of combining the productivity data and typical production curves were used to analyze different geological factors and how to influence the capacity of a single layer. Then, the paper proposed a new understanding about capacity characteristics of the study area and geological control factors： First, the Shanxi formation production capacity characteristics was divided into two-stages, showing signs of gas and gas break- through for 100 days. Second, two parameters, which include potential of gas production and gas production capacity, were bet- ter than the single parameter, such as gas content, coal thickness, and penetration to analyze affecting factors of single well pro- duction. Finally, comprehensive analysis concluded that the ratio of critical desorption pressure to reservoir pressure has greater influence on the production of vertical CBM wells. Besides, the potential of gas production capacity has greater impact at stage of showing gas signs; the coal reservoir pressure and gas production capacity have greater impact at stage of gas breakthrough for 100 days. Thus, to seek the coal bed methane with high ratio of critical desorption pressure to reservoir pressure and high yield of gas will be important guarantee to the success of the coal bed methane exploration and development.

LIULIN TOWN CATTLE MARKET

Liulin Town is situated in MengchengCounty in Anhui Province.Under it,there are 26 villages,a 41,000 populationand 38,000 head of cattle. The Liulin Town Government has paidmuch attention to cattle development in thedirection of scientific and intensive farming.It has six cow fattening farms.The generalfarm was invested with RMB5 million,andeight rows of cowsheds were built for 1.200head of cattle.They can sell 5.000 head ofbeef cattle a year.

柳林区块煤层气井生产动态及其影响因素分析

针对柳林区块煤层气井生产动态影响因素复杂,无法制订合理的增产措施等问题,分析了区内50余口井排采动态规律,探讨了不同类型井产出动态的影响因素。结果表明：区内气井以中低产井为主,初期见气快,后期产气量下降严重。水平井相比于垂直井、丛式井,产气量相对稳定高产。煤层厚度、水文条件是分别影响山西组、太原组煤层产能的主要地质参数,结合工程因素分析认为,区内煤储层敏感性较强,压裂规模以及储层损害是造成区内垂直井低产的主要原因。同时,提出相应的增产参数指标：加砂量大于35 m3,施工液量大于400 m3;排采初期控制液面下降速度为2~10 m/d,产气后套压为0.1~0.3 MPa,减少关井次数,停排采时间小于20 d。

柳林地区煤层气开采动态及单井产量主控因素分析

柳林地区是我国煤层气勘探开发的热点地区之一,初步实现了煤层气商业化开发。根据柳林地区煤层气井生产数据,对气井产气动态进行了分析,按产量大小进行了气井统计,中产气井比例较高,为42.9%,高产气井占28.6%,低和极低产气井比例为28.5%。分析煤层气井排采曲线特征,总结归纳气井的产气模式有单峰式、高峰-稳定式和低峰-高峰-稳定式三类。从影响煤层气产能的构造、气含量、渗透率、煤层厚度、煤层埋深、水文地质条件等地质因素入手,分析了各地质因素对气井产能的影响,并建立各类因素与煤层气井产能的关系。研究认为:柳林地区煤层气井的高产条件并非受单一因素的控制,而是主要取决于多种有利地质主控因素的有机匹配、共同作用的结果。

柳林区块煤层气水平井煤粉产出特征及影响因素研究

为了揭示煤层气水平井产出煤粉特征,开展了柳林区块L1煤层气水平井产出煤粉的现场连续监测,采用精密天平、激光粒度测试仪和扫描电镜对煤粉样品进行浓度测量、粒度测试和形态观察。分析了煤层气水平井在排采过程中产出煤粉的浓度、粒度和形态特征及其影响因素。结果表明,煤粉浓度范围为0.2~6.5 g/L,煤层气井排采参数的突然改变会使煤储层受到气液流的冲蚀,导致煤粉浓度的增加;煤粉颗粒分布范围为1~500μm,煤粉粒度的大小与气液流速有关,排采参数发生变化,气液流速增大会将粒度较大的煤粉带到井口;煤粉颗粒的形态主要为块状和粒状,煤粉颗粒的形态与煤层的煤体结构类型有关,煤粉颗粒有光滑表面和粗糙表面两种,表面常附着有高岭石等无机矿物,煤粉表面特征与煤岩和无机矿物成分有关。

煤层气水平井施工井漏问题及解决办法

根据中国煤炭地质总局一二九勘探队在山西柳林区块煤层气水平井施工中的井漏问题及相应的解决办法进行了总结归纳。对于不同的漏失情况对应的解决办法进行了探讨和总结,对该区水平井施工有一定的借鉴意义。

U型水平连通井在河东煤田柳林地区煤层气开发的适应性分析

柳林地区煤层气开发的主力煤层是山西组的3+4#煤层和太原组的8+9#煤层,煤层端割理发育,盖层封闭性好,构造简单,有利于煤层气储存。以区块FL-EP6H-EP6V"U"型连通井的实际工程研究和优化设计工作为基础,从设备选型的可靠性、井壁的稳定性评价、井位的选择、着陆点的选择、地质导向和完井工艺六个方面,对"U"型水平连通井技术在柳林地区煤层气开发的适应性进行了研究、探讨,提出了引进和使用新的EM-MWD随钻测量仪器,及时控制井眼轨迹,先期在定向点以下施工小井眼以精确确定煤层的着陆点,采用筛管完井解决煤层水平段容易坍塌问题等具体措施,从而证明在该区施工型水平连通井是可行的。

柳林泉岩溶地下水污染与治理措施

柳林泉是吕梁地区最大的岩溶泉 ,属山西省重点保护泉之一 ,也是吕梁地区离柳煤电能源区和离石市、中阳县、柳林县三个县市城市生活的主要水源。从上世纪九十年代开始在不断的变化 ,许多有害元素的检出率从无到有逐渐增加 ,随着水量减少和环境的变化 ,水质将进一步恶化。针对柳林泉的污染状况提出治理措施 ,并能引起有关部门的重视。