多参数交会法识别志丹地区长8_1复杂油水层

鄂尔多斯盆地志丹地区长8储集层地质特征复杂,相对高电阻率水层、相对低电阻率油层与常规油水层共存,测井响应特征复杂多变。在油水层识别过程中,一般测井参数不能将其有效识别,造成有效油层"漏失"和水层的错误识别。针对以上情况,结合大量的测井数据、试油试产和取芯分析等资料,针对志丹地区主要含油层位长81,注重测井单项信息提取及参数的综合应用,采用单井径向电阻率对比法、曲线重叠图法和多井资料交会图综合分析法逐步识别各类流体,最终对油水层进行有效的识别,形成一套合理的流体识别方法。

柴达木盆地乌南油田不同类型储层的解释方法研究

乌南油田整体是以构造控制为主的岩性构造油气藏。同一油组埋深差异非常大具有不同的矿化度,分外围、主体、w9。油气层主要分布于受断层控制的狭长地带,形成w101、绿2、绿6、w4、w5、w6、w9等多个断块油气藏。本文从四性关系入手,开展了w101区域的低阻油层、w9区藻灰岩以及主力区的低产井三种不同类型储层解释方法研究,总结了应用效果,为老区挖潜奠定了基础。

Pore structure effect on reservoir electrical properties and well logging evaluation

The reservoir pore structure controls the reservoir quality and resistivity response of hydrocarbon-bearing zones and thus, critically affects logging interpretation. We use petrophysical data in three types of reservoir with different pore structure characteristics to show that the complexity of pore structure had a significant effect on the effective porosity and permeability regardless of geological factors responsible for the formation of pore structure. Moreover,, the distribution and content of conductive fluids in the reservoir varies dramatically owing to pore structure differences, which also induces resistivity variations in reservoir rocks. Hence, the origin of low-resistivity hydrocarbon-bearing zones, except for those with conductive matrix and mud filtrate invasion, is attributed to the complexity of the pore structures. Consequently, reservoir-specific evaluation models, parameters, and criteria should be chosen for resistivity log interpretation to make a reliable evaluation of reservoir quality and fluids.

Definition and Classification of Low-Resistivity Oil Zones

Although the analysis of the microcosmic mechanism for low-resistivity oil zones has received much attention in China, the intrinsic relationship between low-resistivity oil zones and geological background is still under-developed. Based on the geology and logging analysis, we redefine low-resistivity oil zones. According to their genesis, low-resis- tivity oil zones can be distinguished as five different classes: low-resistivity oil zones formed by tectonic settings, by depositional settings, by diagenetic settings, by invaded settings and those which are formed by the compounding geneses respectively. We make the following observations from this study on the definition and classification of low-resistivity oil zones: 1) A low-resistivity oil reservoir has macroscopic and microscopic unity. 2) The genesis of low-resistivity oil zones varies with the type of petroliferous basin. 3) Some low-resistivity oil zones can be forecasted based on the geological study results. 4) The results in this paper suggest that well logging information is generated from two cause mechanisms, the geophysical factors and the geological setting. Future studies on the geological background cause mechanism and the theory of well logging information will enrich the theory of logging geology and improve the ability to forecast oil zones.

The new finding of Neogene marine low-resistivity light oil field in the western part of Pearl River Mouth Basin

Based on the new finding of Wenchang L low-resistivity light oil field, the finding process, reservoir charac- teristics and pool-forming pattern were studied. The oil-rock correlation, neritic reservoir type, hydrocarbon conduct system and dominant migration and accumulation direction, and new techniques were discussed. The results showed that large amount of hydrocarbon generated by shallow lacustrine mudstone and shale of Eocene Wenchang formation could migrate from sag to Qionghai uplift distantly; neritic shoal-bar reservoir have developed in the 1 st member of Zhujiang formation, dip-sag faults and regional good marine sandstone layers of the 1 st and the 2nd member of Zhujiang formation have constituted hydrocarbon conduct system in Qionghai uplift ; the late fault system which were controlled by Dongsha tectonic movement constructed the connection between lower hydrocarbon and upper neritic shoal-bar reservoir. There- fore, the pool-forming pattern with ＂vertical migration and accumulation, secondary strncture-lithology-dominated＂ was proposed. Finally the enlightenment of exploratin~ new findings was discussed.

文昌13-2油田珠江组一段储层有效厚度物性下限研究

文昌13-2油田珠江组一段资源量丰富,既有大量高泥质成因的低阻油组,也有高阻油层发育。由于低阻油层和高阻油层在矿物组分、物性及电性等方面存在差异,因此有必要重新开展更加细致的储层有效厚度物性下限值研究。研究中采用了孔渗分析法等多种方法来确定储层有效厚度下限值。尤其对传统定性划分的"三段式"孔渗关系分析法进行了改进,对各小段赋予了明确的地质意义,避免了传统定性三段划分的随机性和多解性问题。论文最终厘定了研究区低阻油层孔隙度下限值为19%,渗透率下限为4.7×10^(-3)μm^(2);高阻油层孔隙度下限为20%,渗透率下限为30.9×10^(-3)μm^(2),该结论经测试和测压数据验证可靠。