十屋油田营城组特低渗砂岩储层测井参数计算方法研究

以松辽盆地十屋油田下白垩统营城组特低渗透储层为研究对象,通过对大量岩石物理实验测量结果的综合分析,揭示该地区特低渗透储层的特征,建立了一套合理的孔、渗、饱储层参数模型,并通过对测井、试油、压汞等资料分析,确定了有效厚度下限标准,以满足油田特低渗透储层测井评价的需要,提高了该区目的层段油藏测井解释和有利区预测的精度.     

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.     

松辽盆地南部孤店断陷火石岭组烃源岩评价及预测

烃源岩识别是油气有利目标预测的基础,对致密砂岩油气藏的钻探部署具有重要的指导作用。通过对松辽盆地南部孤店断陷深层烃源岩的有机质丰度、有机质类型和有机质成熟度进行评价,认为孤店断陷火石岭组烃源岩在有机地球化学特征上总体属于好烃源岩。生烃演化分析认为,火石岭组烃源岩处于生烃演化的过成熟阶段,主要生成以甲烷为主的天然气。结合岭深1井热演化史分析,火石岭组烃源岩属于有效烃源岩,是孤店断陷深层重要的天然气来源。对比单一利用三维地震资料、地震属性和波阻抗反演等方法进行烃源岩层识别的优缺点,提出运用波阻抗和瞬时相位相叠合的方法对烃源岩层进行识别更准确。运用此方法对孤店地区烃源岩层进行了精细解释和分析,预测了火石岭组烃源岩的分布范围。     

梨树凹油田核桃园组三段有效储集层研究

针对水下扇等沉积体高泥质含量低渗复杂岩性储层,以梨树凹油田为研究对象,以测井、岩心分析、试油试采资料为依据,确定复杂岩性储层识别的界限,探索性建立了改进的岩性识别模型、泥质含量校正模型、包含泥质含量参数的孔隙度和渗透率解释模型、动态电阻率油层识别模型,在研究区应用后取得了好的应用效果。经试油资料验证,油、水、干层解释准确率88.24%,初步解决了研究区有效储层难于识别的难题,对油田今后调整挖潜具有重要意义。     

稠油油藏泡沫油渗流数学模型的建立

针对目前泡沫油渗流数学模型存在的问题,借鉴拟泡点模型和过饱和模型中拟泡点压力及弛豫时间的概念,通过对3组长岩心衰竭实验进行分析,建立了泡沫油渗流数学模型。模型中将泡沫油视为拟单相流,通过实验分析在泡沫油流动过程中流动介质的有效渗透率与降压速度、原油粘度和含气饱和度的变化规律,提出有效渗透率的数学表达式;认为泡沫油的粘度与相同条件下饱和油的粘度近似相等;将泡沫油的压缩系数视为油相与气相压缩系数的线性组合;同时在模型建立过程中考虑了泡沫油的过饱和现象。为了验证所建模型的正确性,分别将泡沫油渗流数学模型、拟泡点模型、过饱和模型及黑油模型计算结果与实验结果进行对比,结果表明泡沫油渗流数学模型与实验结果吻合程度较好,而其他模型计算偏差较大。     

基于地震属性分析的地层孔隙压力钻前预测模型

钻前准确预测地层孔隙压力是进行井壁稳定状态分析的基础。基于地震和测井信息间的密切联系,提出了利用地震属性预测孔隙压力的新方法。通过神经网络建立已钻井段的井旁地震属性和声波时差测井数据之间的非线性关系模型,以此模型为基础预测未钻地层的声波速度。利用预测结果结合岩石力学模型得到垂直有效应力,最后根据有效应力原理计算地层孔隙压力。该方法有效克服了传统的地震层速度预测模型的不足之处,在油田的实际应用中取得了良好的效果,尤其适用于在勘探新区进行孔隙压力预测。     

低渗透油藏注水开发的生产特征及影响因素

低渗透藏注水困难的原因有低渗透非达西渗流渗透率的变化、油水两相渗流的有效渗透率降低、地层压力降低所引起的压力敏感性伤害和注入水质不合格所引起的不配伍性伤害等。针对这些影响因素，阐明了改善低渗透田注水开发效果的途径。     

渤南洼陷古近系深层有效储层控制因素研究

依据试油、物性、压汞等资料,利用多种方法求取了渤南洼陷古近系深层有效储层物性下限与埋藏深度的定量函数关系。在此基础上,以孔隙度差值和渗透率差值作为对比参数,探讨了沉积作用、地层压力和成岩作用对渤南洼陷古近系深层有效储层的控制作用。湖底扇中扇辫状水道和扇三角洲前缘地层压力为中强超压、处于中成岩A1期为有效储层发育的有利因素,而近岸水下扇和冲积扇地层压力为常压和弱超压、处于中成岩B期和晚成岩期为有效储层发育的不利因素。总体上,沉积相带是形成优质有效储层的主要控制因素,而地层压力对有效储层发育的控制作用强于成岩作用。     

鄂尔多斯盆地北部上古生界致密砂岩储层测井地质评价

根据鄂尔多斯盆地北部上古生界致密砂岩沉积成岩组分和结构上的差异，对储层孔隙结构、物性、含气性和电性的控制作用，按岩性分类建立了上古生界储层的测井解释参数和有效厚度识别方法，避免了岩石骨架等参数的差异对测井响应造成的影响，提高了解释精度。     

岩石压缩系数变化规律研究

通过对十八块岩样的覆压试验结果进行回归分析,得到了岩石压缩系数的变化规律.研究表明:岩石压缩系数随覆压孔隙度、覆压渗透率的增大而增大,岩石压缩系数的变化率通常是随覆压孔隙度、覆压渗透率的增大而增大.岩石压缩系数与覆压孔隙度、覆压渗透率之间的关系大多数呈二次多项式.压缩系数与有效覆压之间通常呈指数递减,压缩系数的递减率通常是随有效覆压的增大而减小.