地质力学特征对矿山深部资源开发潜力评价的影响研究

随着矿产资源的逐渐枯竭和对深部资源的需求增加,矿山深部资源开发成为了矿业领域的一个重要议题。在这一背景下,准确评估矿山深部资源的开发潜力显得尤为重要。地质力学特征,如岩石力学性质、应力—应变关系、断层和裂隙的分布以及孔隙度和渗透性是影响矿山深部资源开发潜力的关键因素。这些特征不仅决定了开采的技术难度和安全性,还影响着环境和经济效益。本文深入探讨了地质力学特征对矿山深部资源开发潜力评价的影响,以提供更有效的开采策略和决策支持。

地质力学特征评价新方法在导向钻井优化中的应用

针对常规导向钻井技术在适用范围、预测能力与运行成本等方面的局限性,在考察岩石物理及力学参数和地球物理信息之间定量关系的基础上,将地震反演、地质统计、地震属性分析、岩石力学方法与钻井工程实际需求密切结合,提出地质力学特征评价新方法,基于其对导向钻井系统进行优化。新技术以常规地震和测井资料为基础,充分结合钻井、录井等实钻信息,钻前建立地质力学初始模型用于钻井设计,钻进过程中参考实钻资料随钻修正并更新钻前模型用于钻井工艺实时优化,其关键环节是准确预测钻头前方待钻地层的强度、地应力、孔隙压力、坍塌压力、破裂压力等力学参数。以井壁稳定预测及其工程运用为重点,论述导向钻井优化中岩石力学理论和地球物理算法结合运用的思路与技术流程,将该方法在西南、西北复杂探区进行应用。现场应用表明,优化的导向钻井系统可以达到理想的参数预测精度与工艺优化效果,指导安全、优质、快速、低成本钻井的能力得到了提高。

高原富水冰碛隧道洞内坍塌成因与处置技术研究——以拉林铁路米林隧道为例

为了解高原富水冰碛地层的工程地质特性,剖析其隧道洞内坍塌的成因,探索其工程处治措施,以拉林铁路米林隧道为例,对上述3个方面进行深入研究,并提出施工注意事项。研究结果表明:1)高原富水冰碛地层透水性较好,低温易冻胀,抗剪强度随围岩含石量和密实度的增加而增大,随围岩细颗粒含量和含水率的增加而减小,地表水、地下水对冰碛地层围岩有较强的浸泡软化和迁移破坏作用;2)冰碛地层中细颗粒含量较高和地下水较为发育等因素相互作用导致围岩失稳,通常是造成富水冰碛地层隧道坍塌的原因;3)对于富水冰碛地层隧道坍塌处治,主要应做好回填碴体和围岩架空区注浆加固,设置安全护拱与塌腔排水系统,并采用合理的开挖和支护方式。

川西坳陷三叠系雷口坡组顶部白云岩储层分布预测

川西坳陷中三叠统雷口坡组顶部发育古风化壳型储层,近期PZ1井在该风化壳层再次获得高产工业气流,显示雷口坡组具有较大油气潜力,但TS1井的失利又显示了气藏的复杂性。川西坳陷雷口坡组顶部雷四上亚段具溶孔的颗粒白云岩是主要储层,优质储层以白云岩坪相为基础,后期发生白云岩化成岩改造。但由于断层及膏岩夹层的干扰,难以根据地震反射结构预测储层。研究发现,川西坳陷雷口坡组顶部表现出独特的断层相特征:坳陷内发育两个弧形小断层带,表现为强断裂变形白云岩相;断层带后方为断层不发育的完整背斜,表现为弱断裂变形白云岩相;坳陷东坡为揉皱膏岩相。利用这一特殊的断层相特征,依据地质力学原理,预测两弧形小断层带为刚性、单层厚度较薄的地层,为白云岩坪边缘相带,储层厚度较薄但裂缝发育;断层带后方完整地块为刚性、单层厚度较大的地层,为白云岩坪中心相带,储层厚度大;小断层带东侧的揉皱带为膏岩发育区。

利用井筒稳定性分析确定砂岩安全钻井液密度窗口

以伊朗西南部某油田Asmari组砂岩储集层为研究对象,研究其中一口垂直井的井筒稳定性,利用FLAC3D软件,根据钻遇地层地质力学特征建立井筒的有限体积模型,监测井壁岩石塑性状态的形成以确定砂岩层安全钻井液密度的上限值和下限值。评估了岩石强度特性、井筒周围主要地应力和孔隙压力对该井安全钻井液密度窗口的影响,敏感性分析结果表明,井壁岩石内聚力和内摩擦角的减小会导致安全钻井液密度窗口大幅变窄;孔隙压力和最大水平应力与最小水平应力之比的减小则会使安全钻井液密度窗口显著增大。此模型便于量化安全钻井液密度窗口的变化,可作为一种油气井钻井方案设计和监测工具。

Rock-forming mechanism of Qingshanjiao intrusion in Dongguashan copper(gold) deposit, Tongling area, Anhui province, China

Dongguashan deposit is a large porphyry-skarn copper（gold） deposit in Tongling ore district. The Qingshanjiao intermediate acid intrusion of Yanshanian had a direct genetic relationship with mineralization. The magma origin, rock-forming dynamic background and rock-forming process were studied, and the rock-forming mechanism of Qingshanjiao intrusion was discussed, based on geological characteristics, detailed observation of petrography and systematic investigation of petrochemistry, trace elements and REE geochemistry characteristics of Qingshanjiao intrusion. The results show that Qingshanjiao rock body belongs to high-K calc-alkaline series with higher LREE elements, Th, Rb and Sr abundance, but depleted in HREE elements, Ba, Nb and Ta. The primary magma originated from the mantle-crust mixtures which were caused by basaltic magma of mantle mixing with syenite magma of partial melting of the lower crust, and the formation environment of Qingshanjiao intrusion was emplaced in the transitional environment from compression to extension. The Harker diagram and hybrid structures of plagioclase and potassium feldspar indicate that the fractional crystallization occurred in the process of magmatic evolution. The petrochemistry, trace elements and REE geochemistry characteristics indicate that the magma was contaminated by crustal material during the rock-forming. These results suggested that the Qingshanjiao intrusion was formed by fractional crystallization and assimilation and hybridization of mantle-crust magma in the transitional environment from compression to extensional.

Tectonic evolution and the analysis of unfavorable geology in a tunnel

Based on the theory of geomechanics and using geologic analytical methods,analyed the fault characteristics, mechanical properties, displacement mode, tectonic system, structural pattern, activity mode of stress, tectonic activity, and tectonic evolution ofthe area of the Xiamen submarine tunnel, the strike NWW 295^(。), which is the main unfavorable geological structure that affects the safety of the tunnel construction; the macrogeological prediction concludes that weathered troughs and groundwater-rich zonesformed by its larger-scale fault fracture zones are the main unfavorable geological bodiesprovides a basis for preventing the geo-logical hazards in the tunnel construction.

Geological division of gas in the Pingdingshan mine area based on its tectonic dynamics characteristics

In this paper,we used tectonic dynamics theories to study the tectonic evolution characteristics of the Pingdingshan mine area,and analyzed the impact of tectonic progressive control on gas occurrence.The study results are as follows:the Pingdingshan mine area has been mainly controlled by multiple squeezing and shearing actions of the Qinling orogenic belt since early and middle Yanshan,forming the tectonic control characteristics of master control in two directions,namely NWW trending and NNE trending;the NWW trending structure is dominated by squeezing and shearing,while the NNE trending structure is dominated by tension.Progressively controlled by the structure,the gas occurrence presents partition and zonation,i.e.compared with the western structure,the eastern NWW-NW trending structure of the mine area is more highly developed,resulting in the mine area gas occurrence distribution characteristics are distinct in the east while indistinct in the west.Based on this,the mine area can be divided into the following two geological dynamic areas:the western half of mine area,namely the Guodishan fault control area,where the NW-SE trending synchronous tension action suffered by the northeast side(footwall) is relatively strong,and compared with the southwest side(hanging wall),its coal and gas outburst seriousness is weak;and the eastern half of mine area,namely the NWW-NW thrust nappe fracture fold control area,which is a serious area of coal and gas outburst,in particular the axial area of the Likou syncline is the intersection compound and combination position of the NW and NE trending structures,a tectonic concentrated area,and the gas pressure and content here are the largest.