回灌条件下地热流体可开采量评价方法探讨

在地热资源评价体系中，目前缺乏统一的回灌条件下的地热流体可开采量的计算方法，本文在总结前人研究成果基础上，结合实例进行了计算，尝试对现有的回灌条件下地热流体可开采量的评价方法进行对比分析探讨。

回灌条件下地热流体可开采量的评价方法及对比分析

为保证可持续发展战略与环境保护战略等发展目标的实现,近几年相关人员越来越重视地热资源的使用。但是在目前现存的地热资源评价体系中,以回灌条件为前提,工作人员并没有找到合适的地热流体开采量的评价方法,因此本文将前人研究结果与当今实际情况相结合,阐述了在回灌条件下,地热流体可开采量的评价方法以及实际对比情况,以供工作人员参考使用。

原位改性流体化采矿科学、技术与工程

为了解决传统方法难以有效开发非常规地质资源能源问题,提出了原位改性流体化采矿方法,即在原位对矿体进行物理、化学性态改造,实施矿物的流体化开采的一种新型采矿方法,系统介绍了这一新型采矿方法的概念与内涵、科学理论、技术原理与关键技术、工程应用领域等核心内容。其突出内涵是在原位,采用物理与化学方法改造矿体与矿物,改造后的矿体多孔化、矿物流体化、矿物提质改性,实现矿物流体化开采。根据矿体性态变化特征,原位改性流体化采矿问题可分为残留骨架和无残留骨架两类问题。科学理论主要包括固流热化学耦合作用下矿体物理与力学特性演变规律、两类问题的固流热化学耦合的非线性理论模型。技术原理包括原位改性流体化采矿的适用性判据、物理改性原理和化学改性原理。建立的三维孔隙裂隙双重介质逾渗理论是该方法适用性确定的主要依据。概括介绍了覆盖的工业与工程领域及其相应的原位改性流体化采矿技术、工程的发展现状及其展望,这些工业与工程领域包括煤层气、盐矿、油页岩、放射性及有色金属矿产、天然气水合物、低变质煤、干热岩地热等。原位改性流体化采矿方法将有力推动极为广泛的、新型的、下一代非常规地质资源能源的清洁高效开发。

国际地面沉降研究综述

文章在介绍国际地面沉降会议历史及2000年第六届国际地面沉降会议简况的基础上,并根据2000年第六届国际地面沉降会议论文,对国际地面沉降研究进展情况分成如下六个方面进行了综述。地面沉降地质因素介绍了古代地面沉降、泥炭层沉降、地震砂土液化地面沉降和海平面上升研究状况。地下流体运移地面沉降方面介绍了以地下水开采为主的地面沉降问题及地面塌陷、天然气开采引起的地面沉降、均匀沉降对建筑结构的破坏和欠固结石英含水层的压密。固矿开采引起的地面沉降问题介绍了非溶解性矿开采引起的大区域沉降和溶解性矿开采导致的地面沉降。地面沉降灾害治理与决策制订介绍了保护威尼斯泄湖不受地面沉降影响的有关措施、地面沉阵引起的法律纠纷和防治地面沉降的社会决策制订。地面沉降测量与监测介绍了土层压缩性研究成果、放射性分层标技术、星载合成孔径雷达干涉监测技术及GPS和G1S在地面沉降监测中的应用。地面沉降计算与模拟介绍了地下水开采引起的地面沉降预测、矿坑涌水地面沉降计算、固矿开采引起的地面沉降预测、天然气开采引起的地面沉降预测和潜水变化所导致的地面沉降计算。

人为因素导致的地面沉降(英文)

天然气、石油、地下水、地热热水和卤水等流体运移出地下储存地层时,地层耗尽了流体而产生压缩变形,这些变形传递到地表表面就形成了人为的地面沉降。在本文中:(1)列举了世界上主要的地面沉降区域;(2)论述了引发地面沉降的力学机制,这些可以量测的地面沉降发生在地下含水层体系、天然气气田和石油油田之上;(3)描述了目前可以用于地面沉降测量和岩石变形原位测试的技术手段;(4)简要介绍了几个地面沉降预测的数值模型;(5)说明了用于控制地面沉降发展和减轻相关环境影响的几种防治措施。

Flow Pattern and Pressure Fluctuation of Severe Slugging in Pipeline-riser System

During the exploitation of offshore oil and gas,it is easy to form severe slugging which can cause great harm in the riser connecting wellheads and offshore platform preprocessing system.The flow pattern and pressure fluctuation of severe slugging were studied in an experimental simulation system with inner diameter of 0.051 m.It is found that severe slugging can be divided into three severe slugging regimes：regime I at low gas and liquid flow rates with large pressure fluctuation,intermittent flow of liquid and gas in the riser,and apparent cutoff of liquid phase,regime II at high gas flow rate with non-periodic fluctuation and discontinuous liquid outflow and no gas cutoff,regime III at high liquid flow rate with degenerative pressure fluctuation in form of relatively stable bubbly or plug flow.The results indicate that severe slugging still occurs when the declination angle of pipeline is 0,and there are mainly two kinds of regimes：regime I and regime II.As the angle increases,the formation ranges of regime I and regime III increase slightly while that of regime II is not affected.With the increase of gas superficial velocity and liquid superficial velocity,the pressure fluctuation at the bottom of riser increases initially and then decreases.The maximum value of pressure fluctuation occurs at the transition boundary of regimes I and II.

太湖南岸地热资源现状及资源潜力评价

根据热储埋藏条件、盖层、导热构造、地形地貌的总体特征,将太湖南岸地热资源区划分为湖州太湖南岸地热资源区、湖州小梅口地热资源区和湖州苍山地热资源区3区。通过计算区内地热流体年开采累计可利用热能量、热储中的热量、热储中岩石的热量和热储中水的热量,得出太湖南岸地热资源区热储中的热量是现有7口地热井年开采累计可利用热能量的1162倍,其中,热储中水的热量是现有7口地热井年开采累计可利用热能量的126倍,热储中岩石的热量是现有7口地热井年开采累计可利用热能量的1036倍,研究表明太湖南岸地热资源区可利用的地热资源丰富、潜力巨大。初步预测太湖南岸地热资源区东西两侧广大区域内均有可能存在丰富的地下热水资源,可作为今后地热资源勘查的重要区域。

安徽省岳西县溪沸地热成因模式及地热资源评价

溪沸地热位于安徽省安庆市岳西县菖莆镇沸溪村,为研究溪沸地热区地热资源分布特征,应用区域物探工作成果和地质资料进行综合分析研究,查明溪沸地热的地质条件、热储特征,并计算确定了地热储量和地热流体可开采量,研究结果显示:地下热水主要受控于断裂带岩石的破碎程度,断裂带岩石破碎程度不同,其地下热水通道、连通程度存在差异性,F2断裂破碎带是溪沸地热区热储层地下热水的主要通道,研究区外东北部,大气降水沿着F2断裂破碎带呈低温上升泉出露和低温异常显示;通过估算地热田地热资源的潜力可知,区内地热田热储中储存的热量和水量分别为2.1756×10^16 J和4808.08×10^4 m^3,而地热流体可开采量为694.75 m^3/d(8.041 L/s)。研究结果为岳西县溪沸地热的开发利用提供了可靠的理论依据。

Study on water loss of the surface stream affected by iongwali mining

In order to study the effect of Iongwall mining on surface stream water, monitoring stations of water flow rate was established. A lot of water flowing data were collected before, during and after Iongwall mining. Based on monitoring data, the effects of Iongwall mining on surface stream water were analyzed. The results demonstrate that Iongwall mining has effects on the surface stream water; and the stream water would be lost and decrease due to Iongwall mining but never go into underground through fractured zone. Also, the mechanism of water loss due to Iongwall mining was presented. The stream water can go into the surface cracks in the intersection of stream and surface cracks, longwall mining subsidence can change the surface stream slope and the downstream water flowing status. The results also show the effects of Iongwall mining on stream water are temporary and about one or two years later, surface stream water can be recovered.

Numerical simulations of water flow and contaminants transport near mining wastes disposed in a fractured rock mass

A numerical tool, called Hydro-Geosphere, was used to simulate unsaturated water flow and contaminants migration around an open pit filled with mining wastes. Numerical simulations had been carried out to assess the influence of various factors on water flow and solute transport in and around the surface openings including recharge, properties of the waste material and presence of fractures in the surrounding rock mass. The effect of the regional hydraulic gradient was also investigated. The analyses were conducted by simulating various 2D cases using experimentally obtained material properties and controlled boundary conditions. The effects of the hydrogeological properties of the filling material(i.e., water retention curve and hydraulic conductivity function), fracture network characteristics and conductivity of the joints were assessed. The results illustrate that fractures control water flow and contaminants transport around the waste disposal area. A fracture network can desaturate the system and improve the regional gradient effect.

宁晋县城区地热资源量计算方法研究

地热资源是一种储存在地球内部的可再生资源,其功能多,用途广。宁晋县地热资源分布广泛,储量丰富。目前城区内有地热井19眼,其中3眼已废弃,可利用热储层均为奥陶系基岩热储层,开发利用方式均以供暖为主。本文以“河北省宁晋县地热资源勘查项目”为依托,在建立地热模型的基础上,对研究区的地热资源量和地热流体可开采量进行了计算,并对工作取得地热田规模进行了评价。研究结果表明:研究区100年内内控制的地热流体可开采量在回灌条件下为122.31×10^(6) m^(3),地热流体可开采热量为3.27×10^(16) J;推断的地热流体可开采量为74.67×10^(6) m^(3),地热流体可开采热量为1.96×10^(16) J,储量查明级别为推断;属于中型地热田。

Computational fluid dynamics simulation on the longwall gob breathing

In longwall mines, atmospheric pressure fluctuations can disturb the pressure balance between the gob and the ventilated working area, resulting in a phenomenon known as ‘‘gob breathing". Gob breathing triggers gas flows across the gob and the working areas and may result in a condition where an oxygen deficient mixture or a methane accumulation in the gob flows into the face area. Computational Fluid Dynamics(CFDs) modeling was carried out to analyze this phenomenon and its impact on the development of an explosive mixture in a bleeder-ventilated panel scheme. Simulation results indicate that the outgassing and ingassing across the gob and the formation of Explosive Gas Zones(EGZs) are directly affected by atmospheric pressure changes. In the location where methane zones interface with mine air, EGZ fringes may form along the face and in the bleeder entries. These findings help assess the methane ignition and explosion risks associated with fluctuating atmospheric pressures.

Determination of protection range of mining upper protective layers and its numerical simulation

Aiming at the limitation of the traditional method for determination of protection region, combined with the actual situation of a mine, a new method for determination of protection region was put forward （including the protection of working face layout and development direction）, that is, gas flow observation analysis on the spot and gas content contrast method. The protection region was determined by gas flow observation analysis, gas content contrast, and computer numerical simulation combined with engineering practice. In the process of gas content test, the fixed sampling method ＂big hole drill reaming, small orifice drill rod connected with core tube＂ was employed. The results show that the determined protection region is in accordance with the actual site situation. The fixed sampling method ensures the accuracy of gas measurement of gas content.

Analysis on air-leakage law of goal in condition of ascending mining for top-coal caving

Using the Jisan Coalmine's top-coal caving for the 3down coal seam with ascending mining as the project background, the air-leakage characteristics of the goaf wasanalyzed. Through data fitting of the in situ observation, the models of gas seepage, diffusion and air-leakage in the goaf were established in ascending mining. The ComputationFluid Dynamics software Fluent was used to simulate the air-leakage law of the goaf. Theresults of the numerical simulation provide a basis for the use of the technology of ventilation and fire prevention in the working face of an ascending mining, which ensures thesafety in production in the working face of the top-coal caving for 3_down coal seam in theJisan Coalmine.

Numerical Study on Viscosity Reduction in Mining Heavy Oil by Circulating Hot Water

Viscosity reduction is an important process in mining heavy oil.To predict the temperature variation and viscosity variation of heavy oil in flow direction,computational fluid dynamics(CFD) was adopted to simulate the process of heat transfer and flow in this paper.Moreover,an objective function,namely viscosity reduction efficiency,was established to analyze the effect of viscosity reduction.The results indicate that circulating hot water can reduce viscosity significantly,and that the effect of viscosity reduction depends on the inlet temperature and inlet volumetric flow rate of hot water.There is a maximum temperature of heavy oil in flow direction.With the inlet volumetric flow rate of 2.0m3/h and the inlet temperatures of 60,℃,70,℃ and 80,℃,viscosity reduction efficiencies are 94.6%,96.7% and 97.3%,respectively.With the inlet temperature of 70,℃ and the volumetric flow rates of 1.5m3 /h,2.0 m3/h and 2.5m3/h,viscosity reduction efficiencies are 94.4%,96.7% and 97.2%,respectively.