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1.
In order to detect hydraulic and geochemical impact on the groundwater directly above the CO2 storage reservoir at the Ketzin pilot site continuous monitoring using an observation well is carried out. The target depth (446 m below ground level, bgl.) of the well is the Exter formation (Upper Triassic, Rhaetian) which is the closest permeable stratigraphic overlying formation to the CO2 storage reservoir (630–636 m bgl. at well location). The monitoring concept comprises evaluation of hydraulic conditions, temperature, water chemistry, gas geochemistry and δ13C values. This is achieved by a tubing inserted inside the well with installed pressure sensors and a U-tube sampling system so that pumping tests or additional wireline logging can be carried out simultaneously with monitoring. The aquifer was examined using a pump test. The observation well is hydraulically connected to the regional aquifer system and the permeability of about 1.8 D is comparatively high. Between Sept. 2011 and Oct. 2012, a pressure increase of 7.4 kPa is observed during monitoring under environmental conditions. Drilling was carried out with drilling mud on carbonate basis. The concentration of residual drilling mud decreases during the pump test, but all samples show a residual concentration of drilling mud. The formation fluid composition is recalculated with PHREEQC and is comparable to the literature values for the Exter formation. The gas partial pressure is below saturation at standard conditions and the composition is dominated by N2 similar to the underlying storage reservoir prior to CO2 injection. The impact of residual drilling mud on dissolved inorganic carbon and the respective δ13C values decreases during the monitoring period. The pristine isotopic composition cannot be determined due to calcite precipitation. No conclusive results indicate a leakage from the underlying CO2 storage reservoir.  相似文献   

2.
Red mud residue from alumina production has been proposed as an alternative liner material. The chemical and environmental compatibility of red mud upon exposure to representative organic (methanol, heptane, TCE, and acetic acid) and inorganic liquids (CaCl2 and seawater) was studied. Chemical compatibility assays comprised Atterberg limits and sedimentation and hydraulic conductivity tests for red mud interacted with the chemical liquids, whereas the environmental compatibility was assessed through the leaching of metals from red mud as permeated with the liquids. Methanol greatly reduced the plasticity at concentrations ≥80 % by volume, but it did not increase the hydraulic conductivity of compacted red mud. High concentrations (≥60 % v/v) of acetic acid reduced the plasticity and enhanced the sedimentation of red mud. Conversely, acetic acid concentrations ≤40 % caused dispersion, but damaged the hydraulic properties and structure of red mud. The percolation of a pH 2 acetic acid solution did not adversely affect the hydraulic performance of the red mud liner. Neither diluted heptane nor TCE affected the red mud. However, pure organics suppressed the plasticity and induced aggregation of red mud, suggesting a great detrimental effect on red mud liners. The red mud exhibited great resistance to attack by inorganic salt solutions. Some concerning leaching of metals (primarily Al and Cr) occurred as water, acetic acid, and CaCl2 solutions percolated through red mud, but effluent metals concentration quickly dropped to permissible levels. In general, red mud exhibited a high resistance against chemical attack; nevertheless, exposure to low-dielectric-constant organic chemicals should be avoided.  相似文献   

3.
易亚东 《探矿工程》2019,46(3):47-50
绿色勘查钻探施工广泛采用便携式全液压钻机,受便携钻机泥浆工艺、占地面积的影响,没有配套的泥浆净化设备,施工中存在浪费水资源、废弃泥浆没有环保处理的问题。综合分析各种泥浆净化方法,提出使用微型高频双层圆形振动筛净化泥浆的方案,效果较好,经济实用,符合绿色勘查要求。  相似文献   

4.
The drilling sludge represents a complex environment, containing several types of pollutants that can be even used as nutrients by indigenous microorganisms, like hydrocarbon-degrading bacteria, having good potentialities for the biodegradation of petroleum products. In this study, a drilling sludge was collected from drilling quagmire. Physicochemical characterization of the drilling sludge was done. Its mineralogy was obtained by diffractometry. The indigenous aerobic sludge hydrocarbon-degrading bacteria were checked by counting on Bushnell–Haas medium, and their isolation and purification were performed by the selective microbial enrichment technique in a batch-enriched Bushnell–Haas culture, with crude oil as the sole carbon source. Isolates were characterized, and their power to emulsify crude oil was determined by emulsification index and oil spreading tests. Environmental conditions in the quagmire, like temperature, pH and moisture, were suitable for bacterial development. Physicochemical characteristics of the drilling sludge showed richness in chemical elements and promote microbial life. Fifteen different colonies of hydrocarbon-degrading bacteria were isolated and purified; they have diversified morphological and microscopic aspects. Most isolates had a good emulsification index (between 31 and 76 %). Oil spreading test gave clear zone diameters >28 mm, with a maximum of 60 mm. The results of these investigations prove the elementary, mineralogy and microbiology richness of drilling sludge and reveal the high diversity of its indigenous hydrocarbon-degrading bacterial flora. These properties can be exploited for the own restoration of petroleum quagmires in oil fields, by means of bioremediation applications and by integrating indigenous microorganisms.  相似文献   

5.
南堡地区东营组一段辫状河三角洲前缘中孔低渗油气藏的非均质性强。本文采用实验室储层敏感性评价实验程序,针对油田钻井和注水开发实际工作条件,进行了多种储层敏感性测试。实验结果表明:该地区中孔低渗储集层在钻探过程中水敏和盐敏性突出,应针对特定井区的储层渗透性计算泥浆滤液浸入深度,对钻井施工进度提出要求;低渗透层泥浆伤害后,渗透率难以恢复,应减少泥浆浸泡时间,选用高效射孔弹,解除泥浆污染。  相似文献   

6.
位于南海西部的莺歌海-琼东南盆地(下称:莺-琼盆地)具有井底压力与温度双高、安全作业密度窗口极窄等特点,在高温高压工况下引发钻井液流变性难以控制、井下恶性漏失、电测仪器阻卡和储层保护难度大等情况.因此,基于此区块复杂的地质条件,经过多次的室内试验研究,在常规聚磺高温高压水基钻井液的基础上,通过引入甲酸钾作为配方抑制剂,同时优选抗高温聚合物以及磺化钻井液材料,在提高了体系的抑制性同时,有效地降低了钻井液的活度,并且通过加重材料的优选,钻井液的流变性得到了改善,使得体系具有较低的高温高压滤失量,密度2.5 g/cm3的体系可以抗高温达240℃.现场实践表明,新型高温高压水基钻井液体系具有良好的抗高温性和流变性,较低的高温高压滤失量,优良的滤饼质量,同时根据电缆测井井壁取心结果,此新型水基钻井液体系的储层保护效果良好.   相似文献   

7.
Oil-based drilling cuttings comprise a large and hazardous waste stream generated by oil and gas wells drilling operations. Oil-based cuttings are muddy materials with high contents of salts and hydrocarbons. Composting strategies have shown to be effective in the biodegradation of petroleum hydrocarbons, and it offers numerous advantages in comparison with other bioremediation methods. In order to assess the effectiveness of drilling cuttings bioremediation by composting with food and garden wastes, an experiment was conducted in 60-L reactors for 151 days. Four treatments were carried out: only oil-based cuttings, two proportions (in a volume basis) of organic wastes to drilling cuttings (33 and 75 %) and only organic wastes (as a traditional composting reference), with pine-tree woodchips as bulking agent. High degradation percentages of total hydrocarbons (≈82 %), n-alkanes (≈96 %) and the 16 USEPA-listed polycyclic aromatic hydrocarbons (≈93 %) were reached in the treatment with 75 % of organic wastes, and applying 33 % of organic wastes was not more effective than not applying organic wastes for the drilling cuttings hydrocarbons biodegradation. Furthermore, in the treatment with 75 % of organic wastes, alkanes half-life and polycyclic aromatic hydrocarbons half-life were about 10 times and four times lower, respectively, than those in the treatment with 33 % of organic wastes. Possibly, lower hydrocarbons and salts initial concentrations (i.e., lower toxicity), higher microbial counts, adequate nutrient proportions and water content supported a high biological activity with a consequent elevated biodegradation rate in the treatment with 75 % of organic wastes.  相似文献   

8.
The influence of alkaline aqueous solutions on the properties of bentonite was investigated to evaluate the performance of bentonitic engineered barriers when contacted with alkaline groundwater. Batch and hydraulic conductivity tests were conducted on Na-bentonite using six different alkaline aqueous solutions. For the batch tests, almost no change in the montmorillonite fraction of the bentonite was observed after reacting with alkaline solutions (pH = 8.4–13.1), regardless of the solution type. On the other hand, aluminosilicate minerals (e.g., albite) were dissolved and secondary minerals (e.g., anorthite) were formed in alkaline NaOH solutions (pH > 13). The cation (Ca or Na) concentration primarily affected the swelling properties of bentonite rather than the pH of the solution, which was comparable to the results of the hydraulic conductivity tests. For the Ca solutions, the hydraulic conductivity of the bentonite specimen to the 0.02 mol/L Ca(OH)2 solution (6.5 × 10?9 cm/s) was approximately an order of magnitude lower than that of the bentonite specimen to the 0.02 mol/L Ca(OH)2 + 1 mol/L CaCl2 solution (5.0 × 10?8 cm/s), whereas the hydraulic conductivity to the 0.02 mol/L Ca(OH)2 + 1 mol/L CaCl2 solution (pH = 11.3) (5.0 × 10?8 cm/s) was slightly higher than that to the 1 mol/L CaCl2 solution (pHi = 8.4) (4.4 × 10?8 cm/s). For the NaOH solutions with pH > 13, the hydraulic conductivity of the bentonite specimen decreased with increasing Na concentration, suggesting that the effect of Na concentration was more dominant than that of permeant pH.  相似文献   

9.
Drilling of a deep borehole does not normally allow for hydrologic testing during the drilling period. It is only done when drilling experiences a large loss (or high return) of drilling fluid due to penetration of a large-transmissivity zone. The paper proposes the possibility of conducting flowing fluid electrical conductivity (FFEC) logging during the drilling period, with negligible impact on the drilling schedule, yet providing important information on depth locations of both high- and low-transmissivity zones and their hydraulic properties. The information can be used to guide downhole fluid sampling and post-drilling detailed testing of the borehole. The method has been applied to the drilling of a 2,500-m borehole at Åre, central Sweden, firstly when the drilling reached 1,600 m, and then when the drilling reached the target depth of 2,500 m. Results unveil eight hydraulically active zones from 300 m down to borehole bottom, with depths determined to within the order of a meter. Further, the first set of data allows the estimation of hydraulic transmissivity values of the six hydraulically conductive zones found from 300 to 1,600 m, which are very low and range over one order of magnitude.  相似文献   

10.
Anatolia region is one of the most seismically active regions in the world and has a considerably high level of geothermal energy potential. Some of these geothermal resources have been used for power generation and direct heating. Most of the high enthalpy geothermal systems are located in western part of Turkey. Alasehir is the most important geothermal site in western part of Turkey. Many geothermal wells have been drilled in Alasehir Plain to produce the geothermal fluid from the deep reservoir in the last 10 years. A blowout accident happened during a geothermal well drilling operation in Alasehir Plain, and significant amount of geothermal fluid surfaced out along the fault zone in three locations. When drilling string entered the reservoir rock about 1000 m, blowout occurred. As the well head preventer system was closed because of the blowout, high-pressure fluid surfaced out along the fault zone cutting the Neogene formation. In order to understand the geothermal fluid effects on groundwater chemistry, physical and chemical compositions of local cold groundwater were monitored from May 2012 to September 2014 in the study area. The geothermal fluid was found to be of Na–HCO3 water type, and especially, arsenic and boron concentrations reached levels as high as 3 and 127 mg/L, respectively. The concentrations of arsenic and boron in the geothermal fluid and groundwater exceeded the maximum allowable limits given in the national and international standards for drinking water quality. According to temporally monitored results, geothermal fluid has extremely high mineral content which influenced the quality of groundwater resources of the area where water resource is commonly used for agricultural irrigation.  相似文献   

11.
针对沁水盆地煤层气钻井中存在的井壁稳定技术难题,采用X射线衍射、扫描电镜、泥页岩膨胀实验、页岩分散实验测试了泥页岩和煤岩体的组构及理化性能,分析了井壁失稳机理。依据"多元协同"防塌原理,研选出了高效包被抑制剂、封堵防塌剂和活度平衡剂,构建了泥页岩地层防塌钻井液体系QSFT和煤层钻开液QSMZ。评价结果表明,QSFT体系的粘度、切力适中,滤失量低、泥饼薄,对200 μm裂缝的封堵承压能力达3.0 MPa;QSFT和QSMZ具有较强的抑制水化能力,并能显著增加岩样单向抗压强度,对煤岩体岩心湿测渗透率的损害均低于30%,干测渗透率恢复值达到95%以上,可作为沁水盆地煤层气井的钻井液和储层钻开液。   相似文献   

12.
For the utilization of deep saline aquifers in the frame of geotechnical use, such as geological sequestration of CO2, H2 or energy storage, a baseline characterization of pristine reservoir rock cores is required to monitor changes in the indigenous microbial communities and pore fluids, and to study alterations in rock characteristics resulting from interaction with geological storage technologies. However, drilling procedures and technical fluids, particularly drill mud, are sources of core contamination. To measure the penetration of drill mud into the cores, three tracers (fluorescein, microspheres, and 4′,6-diamidino-2-phenylindole stained bacteria) were tested under laboratory conditions. The flow of drill mud into core samples was induced by applying uniaxial pressure differentials to the core, and the penetration depth was microscopically determined for each tracer. Fluorescein was extracted from the rock samples and quantified fluorometrically. The results indicate that all tested tracers are suitable for tracking drill-mud penetration. The actual penetration depth seems to be related to differences in mineral composition and texture as well as microfractures. Among all tested tracers, fluorescein labelling is the simplest, cheapest and most accurate method for analyzing the contamination of rock cores by technical fluids. The application of this tracer was successfully applied during two deep drilling campaigns at the CO2 storage pilot site in Ketzin, Germany. The results highlight that the use of tracers is indispensable to ensure the quality of core samples for microbiological and biogeochemical analysis.  相似文献   

13.
The unusually strong typhoons and heavy rainfalls occurred recently in Taiwan have caused major landslides in many reservoir catch basins. The debris from these landslides eventually settled in the reservoir and turned into mud. From soil mechanics point of view, the mud immediately in front of the dam where the reservoir is usually the deepest is a very young, normally consolidated or under-consolidated fine-grained soil. The engineering properties of the reservoir mud are important parameters in the planning and design of schemes to remove the mud. Yet, our knowledge in this regard is very limited. For some of the major reservoirs in Taiwan, the mud is often under more than 40 m of water. How to conduct effective geotechnical site characterization under these circumstances is a challenge. The authors developed techniques to incorporate differential pressure measurements in flat dilatometer (ΔDMT) and piezo-penetrometer (ΔPu) tests to facilitate in situ measurements under water in a reservoir. A series of field ΔDMT and ΔPu tests along with representative soil sampling were conducted at Tsengwen Reservoir in southern Taiwan. The paper describes the techniques of ΔDMT and ΔPu tests, interpretation of available test data to obtain the engineering properties of the reservoir mud, and discusses implications in the future site characterization of reservoir mud.  相似文献   

14.
15.
Flowing fluid electrical conductivity (FFEC) logging is a hydrogeologic testing method that is usually conducted in an existing borehole. However, for the 2,500-m deep COSC-1 borehole, drilled at Åre, central Sweden, it was done within the drilling period during a scheduled 1-day break, thus having a negligible impact on the drilling schedule, yet providing important information on depths of hydraulically conductive zones and their transmissivities and salinities. This paper presents a reanalysis of this set of data together with a new FFEC logging data set obtained soon after drilling was completed, also over a period of 1 day, but with a different pumping rate and water-level drawdown. Their joint analysis not only results in better estimates of transmissivity and salinity in the conducting fractures intercepted by the borehole, but also yields the hydraulic head values of these fractures, an important piece of information for the understanding of hydraulic structure of the subsurface. Two additional FFEC logging tests were done about 1 year later, and are used to confirm and refine this analysis. Results show that from 250 to 2,000 m depths, there are seven distinct hydraulically conductive zones with different hydraulic heads and low transmissivity values. For the final test, conducted with a much smaller water-level drawdown, inflow ceased from some of the conductive zones, confirming that their hydraulic heads are below the hydraulic head measured in the wellbore under non-pumped conditions. The challenges accompanying 1-day FFEC logging are summarized, along with lessons learned in addressing them.  相似文献   

16.
Smectite clay has been proposed for embedding canisters with highly radioactive waste in deep repositories because of its isolating capacity. Montmorillonite-rich bentonite is a premier buffer candidate for many national organizations that are responsible for disposal of such waste. Experience from the use of drilling mud at large depths indicates that other smectite clay minerals are more stable chemically and saponite is one of them. The physical properties of smectitic mixed-layer minerals like Friedland clay are known to be less sensitive to high salt contents and such clay may also be a buffer candidate. Montmorillonite-rich MX-80 clay, Greek saponite with a minor amount of palygorskite, and Friedland clay were investigated in hydrothermal tests with dense samples confined in oedometers with 95 °C temperature at one end, which was made of copper, and 35 °C at the other, for 8 weeks. A 1 % CaCl2 solution was circulated through a filter at the cold end. At the end of the tests, the samples were sliced into three parts, which were tested with respect to expandability, hydraulic conductivity, and chemical composition. The tests showed that while the saponite was hardly changed at all and did not take up any copper, MX-80 underwent substantial changes in physical performance and adsorbed significant amounts of copper. The Friedland clay sample was intermediate in both respects.  相似文献   

17.
Buried valleys are ancient river or stream valleys that predate the recent glaciation and since have been filled with glacial till and/or outwash. Outwash deposits are known to store and transmit large amounts of groundwater. In addition to their intrinsic hydraulic properties, their productivity depends on their hydraulic relationships with the adjacent bedrock formations. These relationships are examined using a steady-state three-dimensional groundwater flow model through a section of a buried valley in northeastern Ohio, USA. The flow domain was divided into five hydrostratigraphic units: low-conductivity (K) till, high-K outwash, and three bedrock units (Pottsville Formation, Cuyahoga Group and Berea Sandstone). The model input was prepared using the data from well logs and drilling reports of residential water wells. The model was calibrated using observed heads with mean residual head error of 0.3 m. The calibrated model was used to quantify flux between the buried valley and bedrock formations. Mass balance was calculated to within an error of 2–3 %. Mass balance of the buried valley layer indicates that it receives 1.6 Mm3/year (≈40 % of the total inflow) from the adjacent bedrock aquifers: Pottsville Formation contributes 0.96 Mm3/year (60 %) while the Berea Sandstone 0.64 Mm3/year (40 %).  相似文献   

18.
为明确渤海湾盆地莱州湾凹陷垦利L油田古近系沙三上段储层物性特征及影响因素,综合利用铸体薄片、扫描电镜、X衍射、孔渗测试、地层测试等多种分析测试手段,结合区域构造背景、沉积体系等相关研究成果,探讨了沙三上段储层物性控制因素,并在油田注水开发中开展了应用。研究结果表明:沙三上段储层平均孔隙度为28.9%,平均渗透率为762.7×10-3 μm2,属于高孔高渗储层,储集空间以原生粒间孔为主,可见次生粒间孔和铸模孔,微裂缝发育;微裂缝平均宽度为180 μm,微裂缝的存在提供了高效渗流通道,使地层孔渗测试结果明显优于岩心测试数据;优质储层的分布主要受体系域、断裂活动和埋藏作用的影响,水进体系域厚层净砂岩是形成优质储层的物质基础,微裂缝发育提高了渗流能力,快速埋藏减缓了储层孔隙水的排出和储层物性的降低。根据优质储层发育特征及生产动态资料,优化水井分层配注,降低平面及纵向上水驱不均,实现了油田均衡驱替。  相似文献   

19.
Removal of hydrogen sulfide by zinc oxide nanoparticles in drilling fluid   总被引:1,自引:0,他引:1  
Hydrogen sulfide is a very dangerous, toxic and corrosive gas. It can diffuse into drilling fluid from formations during drilling of gas and oil wells. Hydrogen sulfide should be removed from this fluid to reduce the environmental pollution, protect the health of drilling workers and prevent corrosion of pipelines and equipments. In this research nano zinc oxide with 14–25 nm particle size and 44–56 m2/g specific surface area was synthesized by spray pyrolysis method. The synthesized nanoparticles were used to remove hydrogen sulfide from water based drilling fluid. The efficiency of these nanoparticles in the removal of hydrogen sulfide from drilling mud were evaluated and compared with that of bulk zinc oxide. The obtained results show that synthesized zinc oxide nanoparticles are completely able to remove hydrogen sulfide from water based drilling mud in just 15 min., whereas bulk zinc oxide is able to remove 2.5% of hydrogen sulfide in as long as 90 min. under the same operating conditions.  相似文献   

20.
Geomechanics is a science dealing with the study of the behaviour of rocks affected by stress. It has various applications in utilisation from oil and gas reservoirs including of the wellbore stability analysis and determination of safe mud window. The main aim of this paper is geomechanical study of Kangan–Dalan reservoir in South Pars gas field in Persian Gulf in south Iran. Seismic waves are affected by physical properties of rocks when passing underground formations; thus, the velocity of these waves is a desired parameter for estimation of geomechanical properties. The velocity of compressional and shear waves has been determined with processing seismic data resulting from vertical seismic profile. In this paper, after calculation of elastic modules of reservoir rock, the imposed stress field was determined and these concepts were used for engineering calculations such as safe mud window, wellbore stability analysis and sand production potential. For well drilling in Kangan-Dalan reservoir, the minimum and maximum mud weights were proposed in average as 1.093 and 2.011 gr/cc and average critical mud weight as 2.48 gr/cc such that if the weight of mud increases, the tensile fractures will be created on the formation and complete loss of mud will happen.  相似文献   

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