低渗致密砂岩气藏SEC储量评估实例分析--以A气田JS气藏为例

在对气藏的地质特征、开发历程以及生产规律充分了解的基础上,确定合理的评估方法、递减率及初始产量等参数的取值,可合理评价气藏的SEC储量,为气藏储量评估提供方法指导。     

储层原生水对页岩气赋存状态与流动能力的影响

储层原生水对页岩气吸附规律和流动能力的影响情况目前尚不清楚,为此选用四川盆地长宁—威远地区下志留统龙马溪组页岩样品,基于吸附平衡法制取不同含水饱和度的实验样品,开展了高压等温吸附实验,探讨不同含水饱和度下页岩等温吸附作用及机理,并运用自主研发的稳态流动实验装置测试了不同含水饱和度下页岩气的流动能力。研究结果表明:(1)页岩储层微米—纳米级孔隙中原生水的存在降低了页岩的吸附能力,含水饱和度为40%时,模拟计算的总含气量比常规认识下的计算结果下降了18%;(2)页岩视渗透率是压力的函数,低压下努森扩散作用使得页岩视渗透率随压力降低而明显上升,当平均压力为5 MPa、含水饱和度达到50%时,与不含水相比页岩视渗透率下降约70%;(3)当含水饱和度低于临界含水饱和度时,水主要以不可动水赋存在微孔和介孔中,对页岩气流动能力影响较小,而大于临界含水饱和度时,水的赋存位置发生改变,导致页岩气流动能力大幅度降低。结论认为,准确认识页岩储层原始含水饱和度及临界含水饱和度,有助于准确计算页岩气储量、合理预测气井产量。     

致密砂岩气藏井网加密优化

采用物理模拟实验与数学评价方法相结合，系统研究了井控范围从500 m逐步加密至100 m(相当于井距从1 000 m加密至200 m）过程中不同渗透率砂岩储层在不同含水饱和度条件时的储量采出程度，揭示了井网加密对提高储量采出程度作用，以采出程度提高5%~10%和大于10%为依据，建立井网加密可行性判识图表，为气藏井网部署和加密方案优化提供了参考依据。实验岩心常规空气渗透率分别为1.63×10^-3 μm²、0.58×10^-3 μm²、0.175×10^-3 μm²、0.063×10^-3 μm²，含水饱和度介于30.3%~71.1%之间。研究结果表明：渗透率为1.63×10^-3 μm²的储层，采出程度总体均较高，除了在含水饱和度高达69.9%时的采出程度与井控范围有关外，其余含水饱和度条件下，采出程度与井控范围关系不大，可以采用大井距开发；渗透率为0.58×10^-3 μm²的储层，采出程度与含水饱和度和井控范围关系密切，随含水饱和度降低、井控范围加密而增加；渗透率为0.175×10^-3 μm²的储层，采出程度受含水饱和度的影响十分显著，只有在含水饱和度≤52.3%时，井网加密优化可提高储量采出程度，当含水饱和度>52.3%时，储量采出程度均较低，一般≤10%，即使井控范围加密至100 m，也难以得到提高；渗透率为0.063×10^-3 μm²的储层，总体上采出程度非常低，即使含水饱和度仅有31.6%，井控范围加密至100 m，其采出程度最高也只有2.3%，因此，该类储层依靠井网加密难以得到有效动用。     

Economic geology value of oil shale deposits: Ethiopia (Tigray) and Jordan

Oil shale is an organic-rich, fine-grained sedimentary rock, containing kerogen, from which liquid hydrocarbons (called shale oil) can be produced. The oil shale deposits in the Tigray region are found in the northern parts of Ethiopia, Eastern Africa. They are of Upper Paleozoic in age, existing as remnants of the Cretaceous erosion period, underlain by tillites and overlain by sandstones. They were formed during the glacial retreat followed by marine deposition of shales in a basin created by the enormous load of the glaciers. The Ethiopian-Tigray oil shale deposits cover an area extending over approximately 30 km², with an average mineable bed-thickness of 55 m, showing on the upper part inter-beds and laminations of shaley limestones. The oil shale resources in this region are estimated to be approximately 4 billion tonnes. The exploitation of the Ethiopian-Tigray oil shale deposits is an excellent alternative to fulfill the fuel and other petroleum products’ demand of Ethiopia. This study sheds light on the oil shale resources in the Ethiopian region of Tigray, as they are fairly investigated, regarding their geological characterization, and future strategies for their exploration and exploitation potential. In addition, the oil shale deposits in Jordan are also moderately investigated, as Jordan is considered a promising country for shale oil, taking into account that Jordan has no other hydrocarbon resources (such as crude oil and natural gas), unlike many other countries in the MENA (Middle East and North Africa) region, as MENA sets on “seas” of oil and natural gas. Furthermore, oil shale in the USA is also briefly investigated, as the USA is being the world’s largest country of oil shale resources and reserves. Also, some other issues related to the oil shale industry are investigated, such as economics, extraction technologies of shale oil, and the environmental impacts.     

Petrophysical evaluation and volumetric estimation within Central swamp depobelt,Niger Delta,using 3-D seismic and well logs

Estimation of hydrocarbon volume is a critical issue for the economic aspect of the petroleum industry. It is very key in production to estimate reserves and after considerable production, to determine the efficiency of recovery and also as a basis for advanced studies such as reservoir simulations. The petrophysical parameters and hydrocarbon volume within the Central swamp depobelt in the Niger Delta has been evaluated from seismic and well logs data. Two reservoirs, GA and GB were delineated from the logs. The lithologies are sand and shale sequences. The trapping system were interpreted from seismic sections as anticlinal and fault closures. Two horizons and several faults were mapped from the seismic sections. The faults mapped are mainly synthetic and antithetic, characteristic of the Niger Delta. The seismic to well tie shows a fairly good match. The average porosity and permeability estimated for reservoir GA are 20% and 1338 md respectively. Similarly, the estimated average porosity and permeability for reservoir GB are 21% and 1392 md respectively. The results show that the oil bearing zones in the reservoirs are porous and highly permeable. There was no gas present in either of the reservoirs. The estimated initial hydrocarbon in place for reservoirs GA and GB are 57.84 MMSTB and 48.43 MMSTB respectively. The results of the research shows that the field has a decent hydrocarbon potential and can be economically produced from.     

无轨设备备件管理及其储备量的计算方法探讨

如何对矿山无轨设备备件进行细化管理,以达到效率高、投资少、费用省的管理目标,是矿山生产中十分重要的问题。本文针对无轨设备备件量化管理应考虑的因素进行了探讨,提出了自己的看法。     

地质统计学在北衙金矿的应用

简述了地质统计学的由来及使用原理,建立了北衙金矿万硐山矿段地质数据库,模拟了金元素变异函数,建立了矿段的三维模型和品位模型,用克立格法估算了储量,并进行了地质解译,探讨了基于该模型之上的实际应用。     

我国煤层气产业发展趋势预测

我国煤层气资源较为丰富,但煤层气产业的发展还处于起步阶段。我国煤层气在成煤和煤化作用地质条件与美国有差异,勘探开发有一定特殊性。目前我国基本具备美国20世纪80年代中后期煤层气的勘探开发条件,类比美国煤层气储量、产量增长模式,预测我国煤层气的发展也将经过探索、起步和快速三个阶段。预测2010、2020与2030年煤层气产量将分别达到100×108m3、300×108m3和470×108m3,煤层气将有效地改善我国的能源结构,成为常规能源的必要补充。     

地质统计学及其在某铜矿山储量计算中的应用

首先论述了地质统计学的基本理论及应用其计算地质储量的方法步骤；然后以计算机为工具，运用地质统计学对某铜矿山铜金属储量进行了分析计算，并将计算结果与真实储量进行了对比分析。通过对比分析，认为运用地质统计学计算储量具有先进性及实用性。     

基于DIMINE的会理拉拉铜矿三维地质建模及储量估算

为较准确地估算出会理拉拉铜矿床资源储量,首先结合已收集的矿区地质勘探及生产勘探数据,建立了矿区完整的地质数据库;其次,为弥补传统二维研究方法无法完整表达地质体空间产出特征的缺陷,根据地质数据库对矿体进行了圈定,利用DIMINE软件的地质模块构建了拉拉矿区完整的地层实体模型及矿体实体模型;然后以矿体三维实体模型为约束,利用距离幂次反比法对Cu、Fe品位进行了赋值,建立了矿体品位模型;最后采用普通克里格法对资源储量进行了估算,得出矿石量约6 435.01万t,Cu金属量约56.9万t,Cu平均品位0.885%,Fe金属量约848.2万t,Fe平均品位13.182%。选择典型矿体作为校验矿体,分别采用垂直断面法与普通克里格法进行了对比分析,结果表明:Cu、Fe品位的相对误差分别为-1.842%、-4.072%,Cu、Fe金属量相对误差分别为-5.4%、-7.797%,相对误差均控制在±10%以内,对于高效开发利用该矿床资源有一定的参考价值。