东营凹陷通王地区中古生界油气成藏要素及成藏模式研究

东营凹陷通王地区中古生界油源主要来自于牛庄洼陷新生界Es4、Es3和Ek2烃源岩,新生界生成的油气在异常压力作用下通过断层、不整合和砂体输导体系向中古生界碳酸盐岩、碎屑岩储层运移。结合油源特征、生储盖组合及输导体系特征,将研究区油气成藏模式归纳为新生古储-复合运移模式,油气藏类型主要有不整合、断层和岩性油气藏。     

中上扬子地区二叠系烃源岩评价与油气生成

中上扬子地区经历了多期原型盆地的复合叠加,按照烃源岩有机碳含量下限标准,在49条踏勘剖面及丰富的烃源岩样品分析基础上,分析了中上扬子地区二叠系烃源岩的沉积环境、分布范围、有机地球化学特征及其油气生成。下二叠统烃源岩分布广泛,为一套区域性优质烃源岩,沉积于深水-次深水陆棚,北部为秦岭南部隆起、西部为康滇古陆-宝兴隆起、南部为黔中隆起和东南部为江南雪峰隆起所包围,母质类型以Ⅰ-Ⅱ1型干酪根为主,是四川盆地二叠系、三叠系气藏的重要气源岩;上二叠统烃源岩主要包括龙潭组、大隆组泥质岩夹煤层,为较好烃源岩,分布广泛,母质类型以Ⅱ2-Ⅲ干酪根为主;研究区二叠系烃源岩总体处于高过成熟热演化阶段。     

南黄海盆地中、古生界油气地质条件研究

南黄海盆地在以中、新生界为主开展的油气勘探历时近30年,至今未获工业油气流。而盆地中、古生界石油勘探程度很低,目前仅只有少数钻井钻遇中、古生界,对其基本油气地质条件认识存在不足。此文运用含油气系统理论和盆地模拟技术,利用钻井资料,类比下扬子陆区石油地质条件研究成果,对下扬子南黄海盆地中、古生界海相地层烃源岩、储层和盖层条件进行了初步研究,为该盆地中、古生界下一步油气勘探指出了有利方向。     

Enhanced oil recovery from carbonate reservoirs by spontaneous imbibition of low salinity water

An experimental study was performed to investigate the impact of low salinity water on wettability alteration in carbonate core samples from southern Iranian reservoirs by spontaneous imbibition. In this paper, the effect of temperature, salinity, permeability and connate water were investigated by comparing the produced hydrocarbon curves. Contact angle measurements were taken to confirm the alteration of surface wettability of porous media. Oil recovery was enhanced by increasing the dilution ratio of sea water, and there existed an optimum dilution ratio at which the highest oil recovery was achieved. In addition, temperature had a very significant impact on oil recovery from carbonate rocks. Furthermore, oil recovery from a spontaneous imbibition process was directly proportional to the permeability of the core samples. The presence of connate water saturation inside the porous media facilitated oil production significantly. Also, the oil recovery from porous media was highly dependent on ion repulsion/attraction activity of the rock surface which directly impacts on the wettability conditions. Finally, the highest ion attraction percentage was measured for sodium while there was no significant change in pH for all experiments.     

Identification of the lower limit of high-quality source rocks and its relation to hydrocarbon accumulation— Taking the Beier Sag in the Hailaer Basin as an example

The theory of “source rock control” has evolved from source-rock-control hydrocarbon accumulation, to effective source-rock-control hydrocarbon accumulation, and to high-quality sourcerock- control hydrocarbon accumulation. However, there are problems, such as whether high-quality source rocks exist or not? What high-quality source rocks are, and how to identify them, are yet to be agreed upon. Aimed at this issue of concern to explorationists, and taking the Beier Sag in the Hailaer Basin as an example, this paper defines the high-quality source rocks and the lower limit for evaluation of high-quality source rocks, by using the inflection point on the relationship curve of hydrocarbon (oil) expulsion, which is calculated by the material balance principle, versus total organic carbon (TOC). The results show that when TOC is low, all source rocks have limited hydrocarbon expulsion and slow growth rate, thus they cannot be high-quality source rocks. However, when TOC rises to some threshold, hydrocarbon expulsion increases significantly with TOC. This inflection point should be the lower limit of high-quality source rocks: those with TOC greater than the inflection-point value are high-quality source rocks. In addition, the lower limit of high-quality source rocks is also related to the type and maturity of organic matters in the source rocks, as well as the mineral components of the source rocks affecting the residual hydrocarbons. Theoretically, the lower limit of high-quality source rocks depends on geological conditions rather than being a constant value. However, for the sake of simplicity and practicability, in this paper TOC=2.0% is regarded as the lower limit of high-quality source rocks. The examination of such standard in the work area indicates that the high-quality source rocks in members K1n2 and K1n1 of the Nantun formation contribute 76% and 82% to oil generation, and 96% and 91% to oil expulsion , respectively. The distribution of high-quality source rocks is also closely related to the distribution of hydrocarbon reservoirs in the region, demonstrating that high-quality source rocks control hydrocarbon accumulation.     

膨胀性岩体隧洞的设计与施工

临汾草峪岭隧洞围岩为二迭系弱－中等膨胀性岩体。这类膨胀性岩体的主要特性为：含粘土量５０％，浸水后膨胀量２－１１％，膨胀压力４４－１７２ｋＰａ，初始含水量高，风化速度快，放置洞外４８ｈ后就风化崩解，最大特点是当其初始含水量损失超过４０％时才产生风化崩解现象，针对此种围岩特性，在隧洞设计施工中采取以下措施，取得了较好效果：（１）光面爆破，短循环开挖，以尽量减少爆破对围岩的破坏作用；（２）快速封闭围岩以     

岩石抗拉强度和断裂韧度的三点弯曲试验研究

断裂韧度和抗拉强度是岩石两个重要的力学特性。利用带切口的三点弯曲梁试验,研究了砂 岩的断裂韧度和抗拉强度特性。对比和分析了带切口三点弯曲和巴西劈裂试验抗拉强度的差别。从理 论和试验上,分析了目前常用的三种断裂韧度计算公式的差别。利用Ｊ积分理论计算了带切口的三点 弯曲梁的断裂韧度ＫＩＣ。研究结果表明:相比于巴西劈裂试验,利用带切口的三点弯曲试验测得的抗拉 强度更加稳定可靠;目前常用的三种断裂韧度计算公式在ａ／ｈ较小时相差不大,但随着ａ／ｈ的增大,差 别越来越大,建议选用ＡＳＴＭ提出的公式;利用Ｊ积分计算得到的断裂韧度ＫＩＣ介于ＡＳＴＭ和Ｔａｄａ给出的 公式计算结果之间,说明该方法是可靠的。     

大型地下厂房洞室群开挖顺序优化研究

地下洞室群的开挖顺序是影响洞室围岩稳定性的主要因素之一.结合拟建双江口水电站厂区地形地质条件及洞室群结构特点,采用三维弹塑性有限元法,研究不同开挖工序下洞室群围岩的应力场、位移场及破坏区分布规律,对围岩的稳定性进行分析,并以开挖过程中对周围岩体的扰动破坏体积最小、应力集中程度最小、最大位移最小作为优化准则,提出了较优的...     

水工压力隧洞内衬及围岩应力与变形数值计算

应用三维快速有限差分软件FLAC3D,对柏叶口水库泄洪发电隧洞进行了数值仿真计算,研究了开挖后高水压作用下洞室特别是泄洪洞与发电支洞交叉口位置管壁及围岩的应力场、位移场及其动态变化规律。结果表明:施加内水压力后,衬砌最大下沉和隆起量均有所减小;在0.78 MPa内水压力下,衬砌管壁局部产生较大的拉应力,将导致混凝土出现较大范围的裂缝;在内水压力下,泄洪洞和发电支洞交叉位置产生较大的拉应力集中,以两洞相交位置小角度一侧应力最大,将出现较大范围的拉裂缝。     

任丘潜山油藏剩余油分布模式及挖潜方向

为了提高任丘潜山碳酸盐岩油藏的最终采收率,开展了地质、测井、物探、油藏工程等多学科的综合研究,提出目前控制潜山油藏剩余油分布的地质因素主要有潜山顶面几何形态、潜山内幕隔层分布和潜山裂缝的发育程度。通过对控制潜山油藏剩余油分布的地质因素的精细描述,总结出了受不同因素控制的剩余油分布模式有六大类九个亚类,指出受内幕构造和裂缝网络控制的剩余油是今后挖潜的重要方向。