苏州马环连接线强风化安山玢岩地质勘察钻探技术

强风化岩体裂隙节理发育,风化程度不均,岩石强度软弱不均,为提高钻进效率,改常规的复合片钻头为孕镶金刚石钻头,使钻进时以研磨岩石方式改为切削岩石方式;为提高岩心采取率,保护取心钻具内强风化岩心及防止钻具内岩心段间相互研磨,改单管钻具为单动双管钻具,采用相对优质泥浆进行护壁,预防钻进及提下钻时的卡钻。     

Method for the determination of residual carbon dioxide saturation using reactive ester tracers

The mechanisms for storage of CO₂ in rock formations include structural/stratigraphic, mineral, solubility and residual trapping. Residual trapping is very important in terms of both containment security and storage capacity. However, to date, the contribution from residual trapping (i.e. immobilisation of supercritical fluid via capillarity in pore spaces) is still relatively difficult to quantify accurately. Using a laboratory-based testing program, this study demonstrates the feasibility of using reactive ester tracers (i.e. triacetin, propylene glycol diacetate and tripropionin), which partition between a mobile water phase and a stationary supercritical CO₂ phase, to quantify the residual CO₂ saturation, S_gr, of a rock formation. The proposed single-well test involves injecting these tracers into the subsurface, followed by CO₂ saturated water, where the ester tracers slowly hydrolyse to form products with differing partition coefficients. After a suitable period of time, allowing for partial hydrolysis, water containing the tracer mixture is produced from the subsurface and analysed using gas chromatography mass spectrometry (GCMS). A numerical simulator of the tracer behaviour in a reservoir is used to explain the differential breakthrough of these tracer compounds during water production to estimate S_gr. Computer modelling suggests that the use of esters tracers to determine CO₂ residual saturation is a potentially robust method. The supercritical CO₂/water partition coefficients directly dictate the amount of time that each tracer spends in the CO₂ and water phases. As such for modelling of tracer behaviour and estimating S_gr, knowing the tracer partition coefficient is essential; in this paper, the first laboratory study to determine the partition coefficients of these reactive ester tracers is described.     

WFSD-4孔深部流体分析和多组分地球化学特征

采用场内钻探流体实时分析和场外钻探泥浆分析的方法,获得汶川地震断裂带科学钻探工程4号钻孔(WFSD-4)中深部井段流体多组分分析结果。研究钻孔深部井段的流体剖面地球化学特征,认为来自地下深部流体在钻探过程中会保存在钻探循环泥浆中,随钻流体实时分析可记录明显的组分变化信号。钻孔岩心的岩性变化易引起钻探泥浆气体的变化,特别是钻探泥浆气体中的多组分变化,在钻孔岩性裂隙较为丰富的井段,是钻探泥浆气体组分变化强度较大区间。通过比较钻探泥浆的多组分和岩心岩性的弱相关性,可以推测钻探流体与余震相关性较强的区域和周期,更可能获得钻探流体与余震的相关程度。     

Impact of drilling mud on chemistry and microbiology of an Upper Triassic groundwater after drilling and testing an exploration well for aquifer thermal energy storage in Berlin (Germany)

After completion of an exploration well, sandstones of the Exter Formation were hydraulically tested to determine the hydraulic properties and to evaluate chemical and microbial processes caused by drilling and water production. The aim was to determine the suitability of the formation as a reservoir for aquifer thermal energy storage. The tests revealed a hydraulic conductivity of 1–2 E-5 m/s of the reservoir, resulting in a productivity index of 0.6–1 m³/h/bar. A hydraulic connection of the Exter Formation to the overlaying, artesian “Rupelbasissand” cannot be excluded. Water samples were collected for chemical and microbiological analyses. The water was similarly composed as sea water with a maximum salinity of 24.9 g/L, dominated by NaCl (15.6 g/L Cl and 7.8 g/L Na). Until the end of the tests, the water was affected by drilling mud as indicated by the high pH (8.9) and high bicarbonate concentration (359 mg/L) that both resulted from the impact of sodium carbonate (Na₂CO₃) additives. The high amount of dissolved organic matter (>?58 mg/L) and its molecular-weight distribution pattern indicated that residues of cellulose, an ingredient of the drilling mud, were still present at the end of the tests. Clear evidence of this contamination gave the measured uranine that was added as a tracer into the drilling mud. During fluid production, the microbial community structure and abundance changed and correlated with the content of drilling mud. Eight taxa of sulfate-reducing bacteria, key organisms in processes like bio-corrosion and bio-clogging, were identified. It can be assumed that their activity will be affected during usage of the reservoir.     

Mineralogical controls on porosity and water chemistry during O2-SO2-CO2 reaction of CO2 storage reservoir and cap-rock core

Reservoir and cap-rock core samples with variable lithology's representative of siliciclastic reservoirs used for CO₂ storage have been characterized and reacted at reservoir conditions with an impure CO₂ stream and low salinity brine. Cores from a target CO₂ storage site in Queensland, Australia were tested. Mineralogical controls on the resulting changes to porosity and water chemistry have been identified. The tested siliciclastic reservoir core samples can be grouped generally into three responses to impure CO₂-brine reaction, dependent on mineralogy. The mineralogically clean quartzose reservoir cores had high porosities, with negligible change after reaction, in resolvable porosity or mineralogy, calculated using X-ray micro computed tomography and QEMSCAN. However, strong brine acidification and a high concentration of dissolved sulphate were generated in experiments owing to minimal mineral buffering. Also, the movement of kaolin has the potential to block pore throats and reduce permeability. The reaction of the impure CO₂-brine with calcite-cemented cap-rock core samples caused the largest porosity changes after reaction through calcite dissolution; to the extent that one sample developed a connection of open pores that extended into the core sub-plug. This has the potential to both favor injectivity but also affect CO₂ migration. The dissolution of calcite caused the buffering of acidity resulting in no significant observable silicate dissolution. Clay-rich cap-rock core samples with minor amounts of carbonate minerals had only small changes after reaction. Created porosity appeared mainly disconnected. Changes were instead associated with decreases in density from Fe-leaching of chlorite or dissolution of minor amounts of carbonates and plagioclase. The interbedded sandstone and shale core also developed increased porosity parallel to bedding through dissolution of carbonates and reactive silicates in the sandy layers. Tight interbedded cap-rocks could be expected to act as baffles to fluids preventing vertical fluid migration. Concentrations of dissolved elements including Ca, Fe, Mn, and Ni increased during reactions of several core samples, with Mn, Mg, Co, and Zn correlated with Ca from cap-rock cores. Precipitation of gypsum, Fe-oxides and clays on seal core samples sequestered dissolved elements including Fe through co-precipitation or adsorption. A conceptual model of impure CO₂-water-rock interactions for a siliciclastic reservoir is discussed.     

Transport of perfluorocarbon tracers and carbon dioxide in sediment columns – Evaluating the application of PFC tracers for CO2 leakage detection

Perfluorocarbon compounds (PFCs) have high chemical and thermal stability, low background levels in natural systems, and easy detectability. They are proposed as tracers for monitoring potential CO₂ leakage associated with geological carbon sequestration (GCS). The fate of the PFCs in porous media, and in particular, the transport of these compounds relative to CO₂ gas in geological formations, has not been thoroughly studied. We conducted column tests to study the transport of perfluoro-methylcyclo-pentane (PMCP), perfluoro-methylcyclo-hexane (PMCH), ortho-perfluoro-dimethylcyclo-hexane (ortho-PDCH), and perfluoro-trimethylcyclo-hexane (PTCH) gas tracers in a variety of porous media. The influence of water content and sediment minerals on the retardation of the tracers was tested. The transport of PFC tracers relative to ¹³CO₂ and the conservative tracer sulfur hexafluoride (SF₆) was also investigated. Results show that at high water content, the PFCs and SF₆ transported together. In dry and low-water-content sediments, however, the PFCs were retarded relative to SF₆ with the degree of retardation increasing with the molecular weight of the PFC. When water was present in the medium, the transport of CO₂ was greatly retarded compared to SF₆ and the PFC tracers. However, in dry laboratory sediments, the migration of CO₂ was slightly faster than all the tracers. The type of minerals in the sediments also had a significant impact on the fate of the tracers. In order to use the PFC tracer data obtained from the ground surface or shallow subsurface in a GCS site to precisely interpret the extent and magnitude of CO₂ leakage, the retardation of the tracers and the interaction of CO₂ with the reservoir overlying formation water should be carefully quantified.     

Let Me Drill a Coring Hole for You,and I will Return You a Telescope Inserted into the Earth

There was a famous saying by Sage Archimedes over 2,000 years ago that giving him a long enough lever and a fulcrum, he would tilt the entire earth. As an old driller, I propose another non‐famous saying that giving me a chance to drill a coring hole, and I will create a telescope to insert the deepest earth for you. Nowadays, drilling is one of most significant methods to collect samples from the deep earth. Those samples are extremely important for geoscientists to focus on the dynamic evolution of deep earth. Therefore, drilling engineering is thought to be inseparable for the geosciences. Unfortunately, some young geologists, especially students majoring on geology, have no meanings of what the drilling is, and of the importance for their geological researches. In this case, education popularization drilling knowledge should be strengthened in future. And we hope that sufficient attention of drilling engineering will be taken by geologists in the world. Moreover, in order to obtain high‐quality cores by various coring drilling methods. Drilling techniques and special coring tools must be continuously developed to successfully perform with regard to a variety of complex geological conditions. We have developed coring tools these years as follows: Splitted core barrel Triple tube coring drill tool, Advanced tube coring tool, Vacuum suction coring tool, Shock‐type coring tool, Long core barrel coring tool, WL‐drilling system with hydro‐hammer, WL‐drilling system with mud motor. These new coring tools have played a very important role in China's scientific drilling program. All in all, without advanced drilling technology, pickup of high quality samples from the deep Earth and geological research on the dynamic evolution will be restricted.     

Impact of modern deepwater drilling and testing fluids on geochemical evaluations

Evaluation of petroleum-fluid properties, hydrocarbon shows, and source-rock characteristics requires new tools to properly recognize and correct for drilling and test-induced contamination, which is increasingly common in modern deepwater field operations. Oil exploration, development, and now production, are more frequently conducted in deeper-water environments where the challenges faced by drilling and operations can severely impact the evaluation of oil and rock geochemistry and fluid properties. Poorly consolidated sediments, swelling clay minerals, and responses to evolving environmental regulations regarding offshore disposal of drill cuttings have resulted in the widespread use of enhanced mineral oil or synthetic-based muds. Also, water-based drilling fluids used in some deepwater operations contain additives that may impact fluid and rock geochemistry. For example, asphalt-based shale stabilizers are added to aid well-bore competency and prevent sticking drill pipe, and polyalkylated glycols are added to depress freezing temperatures and prevent the formation of gas hydrates in the drilling mud. Because these and other additives are often a significant component of water-based muds, they may affect the geochemical signature of fluids and rocks and alter fluid properties. Highly saline brines are another important source of contamination as they are used in completion fluids, water-wet muds, and are emulsified in oil-wet muds. Brine components impact metal contents of petroleum-fluid tests and complicate the determination of formation-water compositions. Despite potential problems introduced by these additives, successful strategies can be devised to accurately access key geochemical and engineering parameters.     

Polar non-hydrocarbon contaminants in reservoir core extracts

A geochemical investigation of oils in sandstone core plugs and drill stem test oils was carried out on samples from a North Sea reservoir. A sample of diesel used as a constituent of the drilling fluids was also analysed. The aliphatic and aromatic hydrocarbons and polar non-hydrocarbons were isolated using solid phase extraction methods. GC analysis of the hydrocarbon fraction of the core extract indicated that contamination may be diesel derived. From analysis of diesel some compound classes are less likely to be affected by contamination from diesel itself including: steranes, hopanes, aromatic steroid hydrocarbons, benzocarbazoles and C₀–C₃-alkylphenols.     

Critical Investigation of Wear Behaviour of WC Drill Bit Buttons

Mining and petroleum drill bits are subjected to highly abrasive rock and high-velocity fluids that cause severe wear and erosion in service. To augment the rate of penetration and minimize the cost per foot, such drill bits are subjected to increasing rotary speeds and weight. A rotary/percussive drill typically hits the rock 50 times per second with hydraulic impact pressure of about 170–200 bar and feed pressure of about 90–100 bar, while rotating at 75–200 rpm. The drill rig delivers a high-velocity flow of drilling fluid onto the rock surface to dislodge cuttings and cool the bit. The impingement of high-velocity drilling fluid with entrained cuttings accelerates the erosion rate of the bit. Also, high service temperature contributes to softening of the rock for increased penetration. Hence, there is a need to optimize the drilling process and balance the wear rate and penetration rate simultaneously. This paper presents an experimental scanning electron microscopy (SEM) study of electroplated (nickel-bonded) diamond drills for different wear modes.     

Artificial neural network model for prediction of rock properties from sound level produced during drilling

In many rock engineering applications such as foundations, slopes and tunnels, the intact rock properties are not actually determined by laboratory tests, due to the requirements of high quality core samples and sophisticated test equipments. Thus, predicting the rock properties by using empirical equations has been an attractive research topic relating to rock engineering practice for many years. Soft computing techniques are now being used as alternative statistical tools. In this study, artificial neural network models were developed to predict the rock properties of the intact rock, by using sound level produced during rock drilling. A database of 832 datasets, including drill bit diameter, drill bit speed, penetration rate of the drill bit and equivalent sound level (L_eq) produced during drilling for input parameters, and uniaxial compressive strength (UCS), Schmidt rebound number (SRN), dry density (ρ), P-wave velocity (V_p), tensile strength (TS), modulus of elasticity (E) and percentage porosity (n) of intact rock for output, was established. The constructed models were checked using various prediction performance indices. Goodness of the fit measures revealed that recommended ANN model fitted the data as accurately as experimental results, indicating the usefulness of artificial neural networks in predicting rock properties.     

Tracers – Past,present and future applications in CO2 geosequestration

Chemical tracers have been used in various C capture and storage (CCS) projects worldwide primarily to provide information regarding subsurface migration of CO₂ and to verify CO₂ containment. Understanding the movement and interactions of CO₂ in the subsurface is a challenging task considering the variety of states in which it exists (i.e. gas, liquid, supercritical, dissolved in water) and the range of possible storage mechanisms (i.e. residual or capillary trapping, dissolved in water, structural trapping or incorporation into minerals). This paper critically reviews several chemical tracer applications and case studies for CCS projects. In many instances, there are parallels (e.g. tracer classes and applications) between tracers in the oil and gas industry and in CCS. It has been shown that chemical tracers can complement geophysical measurements (e.g. seismic) in understanding the formation behaviour of CO₂. Although tracers have been successfully used in many CCS projects, some fundamental information, for example partitioning and adsorption, about the behaviour of tracers is still lacking and this can be an issue when interpreting tracer data (e.g. determining leakage rates). In this paper the deployment and recovery of chemical tracers and their use on various CCS projects are described.     

Determination of arsenic concentration and distribution in the Floridan Aquifer System

Here we report on the different sampling strategies for almost seven years of sampling rocks/sediments for the determination of As within the Intermediate Aquifer System (IAS) and upper Floridan Aquifer System (FAS), a very large and productive limestone aquifer spanning from Georgia into Florida. In the FAS, As contamination has become a recurring problem during aquifer storage and recovery (ASR), particularly in central and south Florida.To investigate these phenomena, samples from solid drill cores and rock cuttings were collected from the Hawthorn Group, Suwannee Limestone, Ocala Limestone and Avon Park Formation. Samples were taken along drill cores and rock cuttings (referred to as ‘interval’ samples) or from particular drill core sections and rock cuttings (referred to as ‘targeted’ samples) likely to contain elevated concentrations of As as indicated by the presence of pyrite, hydrous ferric oxide, organic matter, clay minerals, fracture surfaces, and high permeable (moldic) zones.Arsenic was present in all of the stratigraphic units at low concentrations, close to the global average for As in limestone of 2.6 mg/kg. The highest As concentration was 69 mg/kg. In all units, however, the average bulk As concentration in the targeted samples was substantially higher than that in the interval samples. Based on direct spot measurements by electron microprobe and indirect calculations, pyrite was identified as the main source of As in the FAS. Concentrations in pyrite ranged from less than 100 mg/kg to more than 11,000 mg/kg. Because pyrite is heterogeneously distributed, both vertically and horizontally in the sampled stratigraphic units, the same was observed for the distribution of As. However, As concentrations generally decreased with depth, i.e., highest As values in the Hawthorn Group and lowest As values in the Ocala Limestone and Avon Park Formation. Compared to pyrite, other trace minerals contained much less As.The average As concentrations of the two types of sample media (solid cores and rock cuttings) were quite similar. These results indicate that if simply the average bulk rock As concentration of a geologic unit is the desired outcome of an investigation, either interval or targeted sampling of rock cuttings, seems to be sufficient. This is particularly important when time and money are a factor. This approach could work equally well for any other trace element. Structural sedimentary information, such as fractures, etc., is likely lost, however, when sampling rock cuttings. Thus, if this information is required, solid core samples need to be collected by hollow core diamond drilling.     

西藏鸭湖地区天然气水合物调查井钻探施工技术

西藏羌塘盆地是公认的天然气水合物有利找矿区,钻探取心是鉴别天然气水合物最直接、最准确的手段。为满足天然气水合物钻探需求,制定了大直径取心、低温泥浆护心的技术方案。试制了跟管取心钻具和大直径绳索取心钻具;逐步完善低温泥浆配方;研制出新型高效泥浆冷却装置。在鸭湖地区天然气水合物调查井施工中,克服地层复杂、环境恶劣等难题,完成钻探取样施工,终孔深度700.70 m,岩心采取率满足地质要求。查明了地层岩性、冻土厚度、气源、岩石物性特征等,不仅为天然气水合物资源评价也为其他油气资源调查提供了地质资料、技术支撑和人才储备。     

地质钻探技术与应用研究

钻探技术是取得地下实物资料、验证地下信息推断与解释、最终圈定矿体、计算储量、评估品位唯一的技术手段,是实现取得宏观影响大成果的重要技术支撑.我国钻探技术和装备水平与国外先进国家相比有很大的差距,但近些年来有了长足的发展.通过国家重大科学工程项目“中国大陆科学钻探工程”5158m“科钻一井”的实施,取得了一系列钻探技术成...     

手持式X射线荧光光谱多点测试技术在地质岩心和岩石标本预研究中的应用

目前国内外比较先进的岩心无损测试,主要采用高光谱技术及XRF扫描技术,这两种扫描范围较大的快速分析方法,均存在着精度要求越高测试时间越长、完整岩心数据精度较高、不完整岩心及岩石标本数据精度较差的问题,难以满足馆藏地质标本取样范围小、快速、准确的要求。本文应用手持式X射线荧光光谱分析技术,以多点测试加权平均的计算方法,改善复杂的样品岩性、矿物种类等因素的影响,提高了分析结果的准确性。结果表明:本方法与定量分析结果比较,具有指示半定量范围作用的测试结果超过82%,加权平均值比算术平均值的指示效果提高了近22%,多点测试的准确度得到了明显提高。并且,该方法具有测试元素较多、粗糙标本经微处理后便可随时测试等优点,较好地解决了馆藏地质标本取样的应用问题。通过这次预研究,新发现了部分铅锌矿标本银元素含量较高、Zk0901钻孔(黄沙坪矿区)168.46~171.24 m的Mo元素平均值为0.3%等具有实际意义的研究数据,为馆藏地质标本再利用提供了重要的找矿信息。     

Well-based hydraulic and geochemical monitoring of the above zone of the CO2 reservoir at Ketzin, Germany

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.     

高放废物地质处置阿拉善预选区巴彦诺日公地段目标深度岩体质量预测

高放废物地质处置阿拉善预选区巴彦诺日公地段位于阿拉善地块东部,主要由二叠纪侵入的花岗岩构成,地壳次稳定。通过踏勘,确定了2个钻孔,布置了若干条物探剖面。以这2个钻孔为中心,在17km×17km范围内进行了工程地质测绘,获得了地表结构面分布特征。地表岩体质量以III级岩体为主,地表以下3m~4m处多为I级和II级岩体。根据钻孔岩芯编录和力学试验数据,对岩芯质量进行评价,岩芯整体质量较好,以Ⅰ级和Ⅱ级岩体为主。对比岩体质量和测井数据,发现岩体质量与岩体的物理参数具有明显的相关性。通过和CSAMT剖面上对应位置的对比,建立了岩体质量与电阻率的关系。结合地表岩体质量、钻孔岩芯质量和物探剖面,对目标深度岩体进行了预测：目标深度（600m深左右）岩体质量以Ⅰ级岩体为主,局部有Ⅱ级岩体和Ⅲ岩体。     

莺-琼盆地新型高温高压水基钻井液技术

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.      

Assessing biomarker syngeneity using branched alkanes with quaternary carbon (BAQCs) and other plastic contaminants

Biomarker molecules are valuable for the elucidation of ancient microbial ecosystems and the characterization of petroleum source rocks. For such studies, acquisition of reliable hydrocarbon data and proof of their syngeneity are essential. However, contamination of geological samples with anthropogenic petroleum products during drilling, storage and sampling can be particularly problematic because these hydrocarbons may over-print an original indigenous biomarker profile. To evaluate the extent of contamination of drill core and outcrop material, we studied the distribution of hydrocarbons in 26 rocks from different locations in the world. All rocks had petroleum products on their exterior surfaces. Twenty-two samples also contained surficial hydrocarbons derived from polyethylene plastic, including branched alkanes with quaternary carbon centers (BAQCs) and alkylcyclopentanes with pronounced even-over-odd carbon number preference. Using three examples from the Paleoproterozoic Tawallah and McArthur Groups in northern Australia, we show how indigenous biomarkers can be recognized by comparing hydrocarbon distributions between exterior rock surfaces and the rock interior, and how infiltration of allochthonous hydrocarbons can be assessed through the spatial distribution of characteristic polyethylene derived hydrocarbons in the rock. The methods outlined in this paper give confidence in the interpretation of biomarkers in particularly sensitive applications such as the first occurrences of certain organisms in the geological record and the provenance of organic matter in meteorites.