Correlation analysis between the Aral Sea shrinkage and the Amu Darya River

The shrinkage of the Aral Sea,which is closely related to the Amu Darya River,strongly affects the sustainability of the local natural ecosystem,agricultural production,and human well-being.In this study,we used the Bayesian Estimator of Abrupt change,Seasonal change,and Trend(BEAST)model to detect the historical change points in the variation of the Aral Sea and the Amu Darya River and analyse the causes of the Aral Sea shrinkage during the 1950–2016 period.Further,we applied multifractal detrend cross-correlation analysis(MF-DCCA)and quantitative analysis to investigate the responses of the Aral Sea to the runoff in the Amu Darya River,which is the main source of recharge to the Aral Sea.Our results showed that two significant trend change points in the water volume change of the Aral Sea occurred,in 1961 and 1974.Before 1961,the water volume in the Aral Sea was stable,after which it began to shrink,with a shrinkage rate fluctuating around 15.21 km3/a.After 1974,the water volume of the Aral Sea decreased substantially at a rate of up to 48.97 km3/a,which was the highest value recorded in this study.In addition,although the response of the Aral Sea's water volume to its recharge runoff demonstrated a complex non-linear relationship,the replenishment of the Aral Sea by the runoff in the lower reaches of the Amu Darya River was identified as the dominant factor affecting the Aral Sea shrinkage.Based on the scenario analyses,we concluded that it is possible to slow down the retreat of the Aral Sea and restore its ecosystem by increasing the efficiency of agricultural water use,decreasing agricultural water use in the middle and lower reaches,reducing ineffective evaporation from reservoirs and wetlands,and increasing the water coming from the lower reaches of the Amu Darya River to the 1961–1973 level.These measures would maintain and stabilise the water area and water volume of the Aral Sea in a state of ecological restoration.Therefore,this study focuses on how human consumption of recharge runoff affects the Aral Sea and provides scientific perspective on its ecological conservation and sustainable development.

文明交往视阈下16世纪布哈拉汗国的经济发展

1500年布哈拉汗国的建立拉开了中亚近代史的序幕。乌兹别克人的南下加快了河中地区游牧文明与农耕文明的交往,促使汗国经济发展步入转折期。在继承和变革帖木儿王朝经济制度的前提下,16世纪汗国的农牧经济得到恢复和发展,手工业进一步完善,对外贸易重新活跃,从而对中亚近代文明交往产生了深远影响。乌兹别克人在与河中地区各民族频繁交往的过程中,其经济生活逐渐转向农业,并接受中亚传统的伊斯兰教,从而实现了中亚农耕文明和伊斯兰文化的传承与发展。

19世纪中叶以前布哈拉汗国文化变迁轨迹

布哈拉汗国是于1500年在中亚河中地区由乌兹别克人建立的国家,在中亚近代文明交往中举足轻重。其文化变迁以三大王朝的更迭为界,不同时期的表现特征明显。政权统治、宗教影响力和游牧文明与农耕文明的兴衰影响了19世纪中叶以前布哈拉汗国文化变迁的发展繁荣或停滞衰败。19世纪下半叶伊始,俄国的征服中断了包括布哈拉汗国在内整个中亚的文明进程,使之卷入俄国历史长河之中。总之,这一时期布哈拉汗国各民族创造的文化成果,在丝路文明交往史上留下了浓墨重彩的一笔。

土库曼斯坦阿姆河右岸B区高风险气藏安全钻井技术

在土库曼斯坦阿姆河右岸B区钻井史上,由于存在高压浅层次生气层、高压盐水层、高压高产气藏以及巨厚盐膏层的复杂地层,因而井喷、卡钻、高压盐水结晶导致井筒报废等事故频发,钻井成功率仅为64%,钻井安全风险极高,部分气田已禁止钻井施工。为此,针对性地开展了如下安全钻井技术试验与应用:(1)针对浅层次生高压气层,采用小尺寸领眼试钻,很大程度上减少了井筒容积,使进入井筒油气的量大大降低,减少了加重钻井液,加快了压井作业时间,提高了钻遇复杂层的安全性,同时在浅层气井区外围采用了钻大斜度井定向井强采方案;(2)针对高压巨厚盐膏层,优选了与盐膏层相配伍的欠饱和—饱和盐水钻井液体系,优选了盐岩蠕变模型,建立了盐膏层井眼缩径方程,形成了钻井液密度图版,确定了盐膏层安全钻井液密度,有效地提高了盐膏层段钻井液的抗污染性和抗蠕变性,保证了井筒安全。相关配套技术已推广应用近百口井,钻井成功率达100%,井喷发生率为零,解放了"钻井禁区",较好地解决了该区域高风险天然气井安全钻井难题。

阿姆河右岸B区复杂地层大斜度井和水平井钻完井技术

通过对已钻直井的实钻资料研究,分析总结出该区域地质特点及大斜度井钻井施工难点,通过井身结构与井眼轨迹优化,优选穿越长段盐膏层的钻井液体系及配方,研究成果已在该区域钻成8口大斜度井,钻井成功率100%,经测试产量为该区域直井的2~3倍。通过实钻作业形成了该区域大斜度井/水平井的井眼轨迹控制及复杂盐下气藏安全钻井技术;解决了巨厚盐膏层使用高密度钻井液情况下的定向钻井技术难题;实践了在使用高密度钻井液,喷漏同存、处理困难复杂情况下的完井方式,形成了巨厚盐膏层及高压含硫产层大斜度井特色钻完井技术,目前大量推广的大斜度井正在施工。大斜度井和水平井钻完井技术为该项目地区实施＂稀井高产、少井多产＂的开发方案提供了可靠的技术支撑和产能保障。