轴向重力流沉积作为断陷湖盆斜坡与洼槽带的一种特殊存在,可形成一定规模的岩性油气藏。近年来在二连盆地巴音都兰凹陷西斜坡与赛汉塔拉凹陷东洼槽均发现该类油藏。主要以赛东洼槽赛83X井区为例,刻画了轴向重力流的沉积特征,证明了轴向

针对二连盆地大庙凹陷的构造发育格局以及油气高产富集规律认识不清的难题，利用沉积相研究以及测井地震联合反演的技术手段，研究了二连盆地大庙凹陷的构造发育格局、储层发育模式以及油气高产富集规律，明确了二连盆地大庙凹陷的资源潜力和有利目标区。研究结果表明：大庙凹陷早期主要为冲积扇—扇三角洲—湖泊沉积体系，其中，冲积扇扇中的砂砾岩、远砂坝中的细砂岩及滨浅湖中的砂砾岩是良好储层发育段，半深湖—深湖泥岩是良好生油层发育段；二连盆地大庙凹陷有利油气富集区主要围绕富烃洼陷分布，并优选出二连盆地大庙凹陷阿尔善组、腾一段为有利勘探目标，预计资源量为150.44×10~4t,部署井位1口，预计产能可达10 t/d。研究成果对拓展二连盆地有利油气资源接替区具有重要意义。

Saturation of movable fluid is the key parameter for the potential tight oil production. With high accuracy rate, NMR technology can obtain fluid saturation statistics accurately, but due to its high cost and long term, NMR cannot be widely applied. Therefore, based on core observation, thin slices, scanning electron microscopy, CT image scanning, this paper set a precedent and proposed to combine nuclear magnetic resonance technology and constant velocity mercury injection technology together to quantitatively study the saturation of movable fluid and main controlling factors in tight sandstone reservoirs. The results showed that pore structure has great influence on movable fluid saturation, among which, total mercury saturation, median pressure, and throat radius are predominant. Diagenesis and sedimentation can affect the mobility of reservoir fluids. With an increasing burial depth, compaction, cementation, and metasomatism deteriorate the fluidity of the reservoir, while dissolution improves the fluidity. Channel microfacies, overflow sand microfacies, rupture channel microfacies, and natural dike microfacies are mainly distributed in the study area. Estuary bar microfacies are mainly dominated by type II and III reservoirs, while sheet sand microfacies are mainly distributed with the type III reservoir.

Based on the study's thorough logging records from 74 wells, grain size analysis, spatial analysis of sand thickness and sand ratio, and pertinent regional geological data, a sedimentary microfacies analysis of the Bayanchagan area is conducted using one sand layer as a unit. In addition, the reservoir's microscopic charac-teristics are summarized, and the location of advantageous reservoir areas is predicted. The principal reservoir rock types in the research region are determined to be lithic arkose and feldspathic lithic sandstone, and reservoir physical attributes are also quite poor. Intergranular dissolution pores make up the bulk of reservoir space types, which also include primary pores, secondary dissolution pores, and micro-fractures. Additionally, the delta front and delta plain subfacies are recognized. Eight more sedimentary microfacies are found: sheet sand, estuary bar, underwater distributary channel, underwater distributary bay, overflow thin sand, floodplain, and distributary channel under water. In a sedimentary environment with water penetration, the entire reservoir was produced. The delta diversion plain deposit makes up the lower portion of the FIII, FII, and FI oil layer groups, while the delta front deposit makes up the top portion of the FI oil layer group. The reservoirs may be divided into three groups: type I reservoirs, type II reservoirs, and type III reservoirs by thorough examination of the facies, microstructure, mercury intrusion characteristics, and other criteria. Among these, type I and type II reservoirs with substantial thicknesses, which are favorable for hydrocarbon accumulation, are the main focus of favorable oil and gas area exploration. The investigation's conclusions are instructive for future research.

准确地预测断裂导致泥岩盖层封闭形成时间滞后程度对于正确认识断裂附近油气分布的规律至关重要,但是目前相关研究却很少且缺乏理论依据。为了正确地认识断裂附近油气分布的规律,在研究断裂导致泥岩盖层封闭形成时间滞后程度及其影响因

Abnormally high-porosity zones in deep reservoirs are widely developed in the fourth member of the Eocene Shahejie Formation (Es4) in the fault-step zone of the Bonan Sag, Jiyang Depression, Bohai Bay Basin, China. However, research on reservoir diversity in these abnormally high-porosity zones has focused on the shallow parts of the reservoirs, and their genetic mechanisms remain unclear, restricting further exploration and development. In this study, comprehensive experimental analysis methods, including casting thin-section observation, scanning electron microscopy and digital core analysis were used to quantitatively characterise the pore structure of the different types of reservoirs in the Es4 abnormally high-porosity zone and analyse the genetic mechanism of these relatively high-quality reservoirs. The results indicate great reservoir diversity in the Es4 abnormally high-porosity zone. The main reservoir rocks are fine-to-coarse feldspar lithic or lithic feldspar sandstone with low porosity and low permeability and can be subdivided into three types (A–C). Four three-dimensional pore-structure models were constructed via the Avizo software to quantitatively reveal the reservoir diversity. The results suggest that ‘macropores’ and ‘mesopores’ are the most significant contributors to both the total pore volume and the amount of connected pores. Many ‘macropores’ and ‘mesopores’ are connected by many pore throats in Type A reservoirs, but these are significantly reduced in Type B reservoirs. Type C reservoirs hardly contain any (connected) ‘macropores’ and ‘mesopores’. Comprehensive analyses of the reservoir physical properties, secondary mineral composition and pore structure demonstrate that primary sedimentary conditions, calcite cementation and dissolution are the main factors that determine reservoir diversity in the Es4 abnormally high-porosity zone. Strong dissolution and effective removal of secondary products are the main mechanisms of the formation of Type A reservoirs, whereas strong dissolution failing to remove dissolution products has led to the formation of Type B reservoirs. Primary sedimentary conditions, strong calcite cementation and lack of dissolution are the main causes of failure to form effective pore networks in Type C reservoirs.
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The Linxing Shenfu block is located at the eastern edge of the Ordos Basin. The Upper Paleozoic tight sandstone gas reservoirs have been the focus of exploration in recent years, and are the key gas-producing horizons. The reservoir rocks in this section are densely cemented with micro development of pores and fractures. Permeability is 0.01-53.07mD with average value of 0.9mD and the formation porosity is 0.2-17.68% with average value of 7%, showing that it is a typical low porosity and low permeability reservoir. Reservoir rock samples have the highest quartz content (65% -90%, average 78.8%), followed by clay minerals (8% -22%, average 14.6%). Clay minerals have the highest illite content, followed by kaolinite, illite/ montmorillonite interlayer, and chlorite. The reservoir has strong sensitivity. When the reservoir rocks are in contact with external fluids (drilling fluids, fracturing fluids, etc.) which are incompatible with the reservoir fluids, these fluids cause the clay minerals to hydrate and swell. The particles are broken, migrated, or precipitated to block the pore throat. As a result, the reservoir pore structure is damaged, the percolation capacity and the productivity are reduced, which causes the damage to the reservoir. Therefore, reservoir sensitivity is an important factor restricting oil and gas development in low-permeability reservoirs. The sensitivity of Linxing Shenfu tight sandstone gas reservoir was analyzed through experiments. The research shows that the tight gas reservoir in the Linxing Shenfu block has medium weak velocity sensitivity with a critical flow rate of 0.50 mL/min, weak water sensitivity damage and salt sensitivity damage with a critical salinity of 25000 similar to 30000 mg/L. There also exists weak to moderate weak alkali sensitivity damage in the reservoir with critical pH of 10-11.5. Weak to medium hydrochloric acid sensitivity damage and medium weak to medium strong mud acid sensitivity damage also exist in the reservoirs.

在区域沉积演化背景分析的基础上,以沉积地质学、测井地质学等理论为指导,利用取心井观察与描述、录井、测井、薄片及测试分析等资料,对二连盆地吉尔嘎朗图腾格尔组二段的沉积相进行了划分,结合区域沉积、构造演化背景,划分沉积相类型

Tight sandstone samples from the Gao 3 and Gao 4 members of Gaotaizi reservoir in Qijia area of the northern Songliao Basin were targeted as the main research objects in this paper. Through micro/nano CT technology and auto skeleton module and connectivity module in avizo software, three-dimensional models for the micro pore structure of Gaotaizi tight sandstone in the research area were constructed. The experimental results demonstrate that types of reservoir space include intergranular dissolution pores, intragranular dissolution pores, and micro-fractures, indicating remarkable microscopic heterogeneity with characteristics of a continuous distribution in a micronano scale. Under the micro scale, different physical property and sedimentary microfacies of tight reservoir show various pore structure characteristics in three-dimensional space, with the primary front of pore throats mainly distributed in 0.61.5 mu m. Under the nanoscale, micro heterogeneity is remarkable, with the primary front of pore throats distributed in 40100 nm. In addition, the nanopore distribution pattern in three-dimensional space mainly includes the nanopores in the granules and the nanofractures, of which the latter type plays a crucial role in connecting nanopores and migration of nano oil and gas migration; at the same time, this paper verify the digital core experimental results by using MICP technology. With the further development of big data technology and deep learning technology, three-dimensional digital core technology based on micro/nano CT technology will become an important technology applied in the exploration and development of unconventional oil and gas.

松辽盆地北部敖南区块是我国重要的致密油资源潜力区,其下白垩统泉头组主要为浅水三角洲前缘水下分流河道砂体沉积,整体为"泥包砂"特征,厚度薄,规模较小,地震反演等常规地震预测技术无法准确地识别和预测该类砂体。通过蓝色滤波目标处理提高了地震资料品质和分辨率;开展了敏感地震属性优选和分析,定性地预测了薄层砂体宏观分布特征;利用井-震联合地质统计反演和随机协模拟技术,对薄层砂体进行了定量预测,刻画了扶余油层主力层砂体的空间分布。预测结果与钻井吻合较好。该方法对其他地区致密油气开发也具有指导意义。