射孔和酸化压裂技术在地热井洗井中的应用

北京YRG-1地热井由于后期技术套管井段"戴帽"固井失误,导致水泥浆下窜堵塞了热水储层的孔隙通道,造成地热井基本不再出水,后经应用射孔和酸化压裂技术洗井,地热井基本恢复了原来的产能,增产效果十分明显。结合工程实例,介绍了射孔和酸化压裂技术在地热井洗井中的应用。     

“压稳防漏”固井工艺在旬邑-宜君区块的研究与应用

旬邑—宜君区块位于鄂尔多斯盆地伊陕斜坡南与渭北隆起结合部,目前处于开发初期阶段。由于三叠系延长组地层沉积环境及后期构造运动的原因,形成地层不整合接触裂缝和地层应力裂缝,造成在钻井与固井过程中易发生漏失,导致水泥浆上返不足,上部井段未得到有效封固。本文通过对工区地层情况、钻进方式和设备、水泥浆浆柱结构以及施工工艺方面进行研究,探究漏失发生的主要因素。为达到提高油气层封固质量的目的,在工程上针对性地提出防漏措施,优化水泥浆配方,使浆体具有一定堵漏性能,依据“压稳防漏”平衡固井理念,更改浆柱结构和施工工艺。通过采用新技术措施后,工区内油气井环空水泥浆返高及胶结质量满足后期压裂改造要求。     

深水油气固井水合物储层物性响应与高压气水反侵研究

固井作业是能源开采过程中的一道重要工序,当深水油气固井遇到水合物地层时,固井水泥浆水化放热会引起近井壁储层中水合物分解和产生高压气水反侵,从而严重影响固井质量,甚至导致固井报废和井壁失稳,为减小和避免水合物分解的不利影响,明确不同固井工艺条件下水合物储层的物性响应和高压气水反侵规律是关键。以南海神狐海域水合物钻探工程GMGS-1中SH2站位勘探井为研究对象,建立固井二维数值模型,采用TOUGH+HYDRATE数值模拟软件再现固井水泥浆侵入和水化过程,分析过程中近井壁储层物性响应规律,得出南海水合物储层不同固井压差与水泥浆放热速率条件下高压气水反侵的临界条件判别曲线,并创新性地采用“连续分段模拟”思路解决水泥浆的动态放热问题。结果表明:水泥浆初凝之前主要可分为诱导、分解和二次水合物生成3个阶段;侵入行为主要发生在保压时期,当压力卸去后侵入深度基本不再增加;水化放热造成的温度升高导致水合物大量分解,产生的高压气水向四周运移,而压力卸去之后,高压气水向环空方向反侵的趋势更加明显;水化放热速率越大,固井压差越小,气水反侵发生的可能性越大,发生时间越早。对于浅部水合物储层,降低固井水泥浆水化热可有效减少反侵现象的发生,提高固井质量,而对于埋藏较深的储层可在破裂压力范围内同时使用较高的固井压差。本研究对水合物地层固井工艺参数优选具有良好的指导和借鉴作用。      

山西干热岩GR1井高温固井技术研究与实践

固井质量对干热岩后期开发利用具有重要意义。针对山西大同盆地干热岩勘查井GR1井温度高、高温固井水泥浆技术体系不完善等问题,通过研究勘查区地质特征,提出了高温固井水泥浆技术体系开发思路。研究表明：干热岩高温固井水泥浆水胶比控制为0.45,优选添加剂高温降失水剂CG82L、高温缓凝剂H40L、高温稳定剂CF40L、消泡剂GX-1、硅粉及HV-PAC,形成一套适用于山西干热岩井的高温固井水泥浆技术体系。该水泥浆体系在GR1井成功应用,现场固井质量良好,研究成果为今后同类型高温固井工作提供了宝贵经验和技术支撑。     

汶川地震断裂带科学钻探项目WFSD-2孔防漏固井技术研究与应用

汶川地震断裂带科学钻探项目二号孔（WFSD-2）钻探施工过程中,地层破碎,坍塌、掉块严重,钻进过程中发生多次井漏。为防止固井过程中发生漏失影响固井质量,采用低密度防漏水泥浆常规单级固井工艺。经过多次水泥浆性能试验,调配出了既具有良好流动性、又具有触变性的低密度纤维防漏水泥浆配方。该低密度纤维防漏水泥浆体系在WFSD-2孔Ф168．3mm套管固井中施工顺利,应用效果良好。     

延长油田西部区域水平井固井水泥浆体系优化技术

分析了目前延长油田西部区域固井现状及造成固井质量差的原因,据此提出了适合延长油田西部地区水平井固井水泥浆性能的要求,优选出了适合该地区水平井固井的水泥浆体系。该水泥浆体系具有低滤失、零自由液、高沉降稳定性、好流变性,有利于提高浆液顶替效率。形成的水泥石具有不收缩、微膨胀、早强的特点,满足水平井射孔、后期压裂改造等工程施工的要求。最终形成了一整套适合延长油田西部地区水平井固井的水泥浆体系。     

泡沫固井水泥浆密度与环空液柱压力变化规律研究

超低密度泡沫水泥浆是解决低漏失压力井固井漏失,提高固井质量的有效措施。除泡沫水泥浆体系的开发与性能优化外,掌握泡沫水泥浆在环空内产生的静液柱压力随井深的变化规律,是成功实施该工艺技术的前提。借助实际气体状态方程,考虑温度、压力变化对充入氮气的影响,建立了静液柱压力和水泥浆密度与井深之间的数学模型,以迭代法编程求解该隐函数方程,并借助VB语言实现程序运算。分析了含气量变化、井深等因素对泡沫水泥浆密度及静液柱压力的影响规律,并提出了泡沫水泥浆“防漏”与“压稳”固井浆柱结构设计思路,为该工艺平衡压力固井设计提供了一定的参考和理论依据。该设计方法经现场应用,证实其运算结果的可靠性。     

水合物地层低热固井水泥浆用相变微胶囊的制备及应用

当深海固井遇到天然气水合物地层时,由于水泥浆水化放热,导致水合物的相变平衡条件发生改变,诱发水合物分解,引起二界面胶结质量下降等问题。为提高水合物地层固井质量,可向水泥浆中添加具有吸热控温作用的相变微胶囊,可有效降低固井水泥浆的水化升温。基于此,以配比石蜡为控温芯材、碳酸钙为壁材,利用自组装法制备了一种使用于深水水合物地层固井水泥浆控温微胶囊。由于固井水泥浆在达到水合物地层的过程中,外界温度环境复杂,单一相变温度的控温芯材极易失效。为扩展控温区间,选用切片石蜡与白油作为混合芯材,控温区间达到14.8~39.8 ℃。研究表明,该微胶囊表观形态良好、彼此无团聚,在热循环过程中,不易发生泄漏。与水泥浆复配后,对水泥浆流变性能无明显影响。在低掺加量时,微胶囊主要起降低水泥浆峰值温度的效果,并提升水泥石整体力学强度;高掺加量时,微胶囊既可以有效降低水泥浆峰值温度,也可以明显地延缓水泥浆放热速率。     

红河油田低压易漏地层水平段固井技术

为提高红河油田水平井固井质量,满足后期分段压裂需求,对红河油田水平井固井技术进行了研究。针对红河油田水平段固井技术难点,通过室内和现场试验,优选出了GSJ水泥浆体系,基于实测地层压力与地层破裂压力,进行平衡压力固井设计确定了环空浆体结构,为提高顶替效率,优化了扶正器类型与加放位置,专业软件模拟表明套管居中度＞73%,良好的井眼准备和套管漂浮措施确保了管柱的顺利下入;加长胶塞、树脂滚轮刚性旋流扶正器和关井阀等附件的使用,保证了固井质量。现场应用53口水平井,水泥浆全部返至地面,CBL测井结果表明,固井优良率达81.13%。该固井技术成功应用于红河油田水平井中,保证了固井质量,满足了后期分段压裂的需要。     

水泥浆灌注时替浆量的确定

水泥浆护壁堵漏的成功率目前仍只达到50～70%,其原因固然多方面,而水泥浆在孔内能否不被稀释,即替浆量是否适当,是其中极重要的一个方面. 准确的替浆量能使钻杆内外的流体(水及水泥浆)在静压平衡状态时(图1),达到同一高度(h_4=h_2,h_3=h_1),在提升钻杆的过程中,钻杆内外的水泥浆互相混     

The terrestrial fauna of the Late Triassic Pant-y-ffynnon Quarry fissures,South Wales,UK and a new species of Clevosaurus (Lepidosauria: Rhynchocephalia)

Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.     

The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts

The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H₂O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H₂O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.     

Quaternary stresses revealed by calcite twinning inversion: insights from observations in the Savonnières underground quarry (eastern France)

Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ₁ roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).     

HYDROGEOLOGY

正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level     

METAMORPHIC PETROLOGY

正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7),     

SERIALS

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GEOPHYSICAL EXPLORATION

正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci-     

QUATERNARY GEOLOGY & GEOMORPHOLOGY

正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli-     

PETROLEUM GEOLOGY

正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.)     

GEOCHEMISTRY

正20142002 Wei Hualing(Institute of Geophysical and Geochemical Exploration,Chinese Academy of Geological Sciences,Langfang065000,China);Zhou Guohua Element Content and Mineral Compositions in Different Sizes of Soil in Tongling Area,Anhui Province(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(11),2013,p.1861