深部盐岩层绳索取心钻井液技术研究与应用

由于次生应力场的作用以及盐岩易溶于水的特性,深部盐岩层钻进存在岩层蠕动、钻井液易遭受盐钙侵等问题;钻进参数选择不合理易导致盐岩层取心效率低、岩心冲蚀严重。本文以河南省叶舞凹陷ZK3井为例,采用石油钻井与绳索取心相结合的措施,解决了普通固体矿产钻探设备在深部地层取心中效力不足的问题;通过阳离子交换容量测定、矿物组分鉴定、钻井液体系优选及性能测试等试验,确定了针对上部泥岩地层的聚合物钻井液体系,中部含膏泥岩的欠饱和盐水钻井液体系,下部盐岩层取心段的饱和盐水钻井液体系。通过确定合适的钻井液密度与临界环空返速,可以有效控制深部盐岩层蠕变与井壁冲蚀,适度提高排量以成倍提高钻进速度。钻进过程中钻井液性能稳定,体系转换顺利且性能易于调整,为取心任务的顺利完成提供了有力保证。     

Influence of bare soil and cultivated land use types upstream of a bank gully on soil erosion rates and energy consumption for different gully erosion zones in the dry-hot valley region,Southwest China

This study assessed temporal variation in soil erosion rates in response to energy consumption of flow (ΔE). It employed an in situ bank gully field flume experiment with upstream catchment areas with bare (BLG) or cultivated land (CLG) that drained down to bare gully headcuts. Water discharge treatments ranged from 30 to 120 L Min⁻¹. Concentrated flow discharge clearly affected bank gully soil erosion rates. Excluding minimal discharge in the CLG upstream catchment area (30 L min⁻¹), a declining power function trend (p ≤ 0.1) was observed with time in soil erosion rates for both BLG and CLG upstream catchment areas and downstream gully beds. Non-steady state soil erosion rates were observed after an abrupt collapse along the headcut slope after prolonged scouring treatments. However, as the experiment progressed, ΔE and energy consumption of flow per unit soil loss (ΔEu) exhibited a logarithmic growth trend (p < 0.1) at each BLG and CLG position. Although similar temporal trends in soil erosion and infiltration rates were observed, values clearly differed between BLG and CLG upstream catchment areas. Furthermore, Darcy–Weisbach friction factor (f) values in the CLG upstream catchment area were higher than the corresponding BLG area. In contrast to the BLG upstream catchment area, lower ΔEu and higher soil erosion rates were observed in the CLG upstream catchment area as a result of soil disturbances. This indicated that intensive land use changes accelerate soil erosion rates in upstream catchment areas of bank gullies and increase soil sediment transport to downstream gullies. Accordingly, reducing tillage disturbances and increasing vegetation cover in upstream catchment areas of bank gullies are essential in the dry-hot valley region of Southwest China.

     

湖北铜绿山铜铁矿床中煌斑岩的矿物学特征及岩石成因初探

湖北铜绿山矽卡岩型铜铁矿床处于长江中下游铁铜成矿带西部的鄂东南矿集区。最近我们在该矿区工作中采集到两条侵入于含矿石英二长闪长玢岩中的煌斑岩脉。本文对这些煌斑岩脉进行了详细的镜下岩相学观察,并对其中造岩矿物黑云母、辉石和长石进行了电子探针成分分析。根据这些数据本文论述了煌斑岩的物源、形成环境以及岩浆体系的物理化学条件。研究表明,煌斑岩中云母为富镁黑云母,其形成的岩浆体系处于中低氧逸度(近Ni-Ni O);黑云母与全岩都具有高钛特征,表明煌斑岩的物源深度可能来自较深部地幔(如软流圈)。煌斑岩中辉石为单斜辉石,环带较为发育,有韵律环带和正环带,其韵律环带的形成可能是由于岩浆温压环境存在振荡性变化而形成的。铜绿山矿床中煌斑岩属于云煌岩;其岩浆来源具幔源性,受到地壳的混染作用不强。     

2008年汶川地震(Ms8.0)非对称同震破碎带的确定:来自WFSD-1随钻流体的证据

地震过程中相当可观的一部分能量消耗于裂隙的活化与形成,来自汶川地震断裂带科学钻探一号孔(WFSD-1)的随钻流体表明,地震新形成的裂隙对应有较强的流体异常,它们为流体的入侵提供了良好的通道。随钻流体呈非对称性分布于主滑移面的两侧,主要的流体异常带集中在主滑移带下方须家河组顶部120 m范围内,该带中气体的含量以及变动的频率明显高于上部相同的宽度范围以及下部沉积岩层,来自地球物理测井的资料同样显示这一带破碎严重并伴随有大量水的侵入,暗示汶川地震形成的裂隙具有非对称性分布的特征。这一特征可能同时受控于断裂上盘彭灌杂岩与下盘须家河组岩层的力学性质差异以及地震破裂过程中形成的非对称性应力分布。     

PDC钻头切削齿布齿设计的新思路

切削齿布齿设计是PDC钻头设计的关键。为提高PDC钻头的钻进效率,综合考虑PDC钻头切削齿的设计特点和切削先后顺序等因素,并且通过对PDC钻头单切削齿实验结果进行分析,提出了以冠部轮廓法线为基准的切削齿布齿设计方法。     

高应力区砂岩加卸载条件下能量变化规律及损伤分析

根据高应力区砂岩三轴压缩试验和峰前卸围压试验的结果,分析了砂岩在不同应力路径下的能量变化规律。试验结果表明,相同围压下,峰前卸围压试验的各能量指标(总吸收能、弹性应变能、耗散能)均小于三轴压缩试验,能量变化特征与其初始应力路径密切相关,且随围压的增大而增大。峰前储存的弹性应变能比耗散能多,耗散能只在临近峰值点处才迅速增加。能量的耗散会导致岩石产生损伤,并且使岩性劣化、丧失强度,从能量角度定义的损伤变量,可以得出结论:开始卸荷低围压下的损伤变量大于高围压下,临近破坏时高围压下的损伤变量大于低围压下;卸围压使岩样束缚减小,加速了损伤的发展,岩样所受的应力状态愈趋不平衡。因此,基于能量的角度来表征岩石的损伤演化更符合实际。     

Review of the Metallogenic Regularity of Magnesite Deposits in China

China has abundant reserves of magnesite, making it the world’s leading source of this strategic mineral. Sparry magnesite is the main type of magnesite deposit, and is easy to exploit. It occurs mainly as the sedimentary-metamorphic type. Production is centred on eastern Liaoning Province, where a world-class large to super large magnesite ore processing and production facility has been developed. Hydrothermal metasomatic deposits, associated with ultramafic complexes and eluvial deposits produced by weathering, are two other important types found in China. The Western section of the Bangonghu-Nujiang metallogenic belt is an important target region for prospecting lake-sedimentary magnesite deposits. Based on a systematic analysis of material from 62 magnesite production areas, this study investigated the metallogeny of magnesite and delineated 13 magnesite metallogenic belts. Maps were produced showing metallogenic regularities in magnesite deposits, the metallogenic system of the magnesite deposits, and the distribution of the metallogenic belts of Chinese magnesite deposits. It provides a theoretical basis for forecasting the location of potential magnesite resources in China. Finally, it explores some key scientific issues, including the formation processes of ultra magnesite ore-concentrated areas, and their sources of magnesium.     

塔里木盆地东北部中—上奥陶统沉积物源与构造背景相关性分析

基于塔里木盆地库鲁克塔格露头区却尔却克山、元宝山和南雅尔当山中—上奥陶统宏观沉积特征分析,结合钻井、地震资料分析,对盆地东北部巨厚的中—上奥陶统碎屑岩沉积物源及其构造背景相关性进行了探讨。中—上奥陶统却尔却克组发育复理石建造,综合重矿物组合、矿物成熟度参数、砂岩主、微量元素、稀土元素和阴极发光等提供的物源信息,反映物源区主要为大陆岛弧和活动大陆边缘构造背景。却尔却克组沉积早期物源区主要来自北部古陆,主要为酸性花岗岩类和变质岩类,却尔却克组沉积中后期,除来自北部的物源外,还有来自东南部阿尔金造山带的火山碎屑物质的加入。中—上奥陶统沉积物源分析为塔里木盆地东北部地区中晚奥陶世构造隆升与沉积充填关系研究提供重要依据。     

闽北地区中侏罗世火山岩的发现及其地质意义

中侏罗世火山岩在东南沿海分布极少,但对区域中生代构造-岩浆活动过程及大地构造演化的研究具有重要意义。在闽北地区大面积白垩纪火山岩区调查中,在政和铁山地区发现中侏罗世火山岩,用LA-ICP-MS同位素测试技术测得的锆石U-Pb年龄为173.63±0.80Ma。火山岩属钙碱性系列流纹质熔结凝灰岩,显示过铝质、富钾、富集大离子亲石元素,亏损高场强元素等地球化学特征,推断其形成于陆缘弧环境,与古太平洋板块早期俯冲作用有关。