【摘要】：甘谷驛油田位于陜西省延安市寶塔區(qū)與延長(zhǎng)縣交界處,構(gòu)造位置位于鄂爾多斯盆地次級(jí)構(gòu)造單元—陜北斜坡的東南部,區(qū)域地質(zhì)活動(dòng)較弱,三疊系延長(zhǎng)組長(zhǎng)6油層組是該油田最重要的含油層系。其長(zhǎng)6儲(chǔ)層總體表現(xiàn)為礦物成熟度低、結(jié)構(gòu)成熟度較高,且所形成的油藏具有低孔、低滲、低含油飽和度的特點(diǎn)。前人對(duì)甘谷驛油田其他區(qū)域的沉積相及油藏特征研究較多,但對(duì)于張羅溝區(qū)的科研工作相對(duì)較薄弱,基礎(chǔ)地質(zhì)研究程度低。因此,對(duì)該區(qū)的沉積項(xiàng)和儲(chǔ)層特征進(jìn)行深入研究,可為該區(qū)的儲(chǔ)量計(jì)算及編制開發(fā)方案提供依據(jù)。本文在區(qū)域地層對(duì)比基礎(chǔ)上,結(jié)合鉆、測(cè)井等資料對(duì)延長(zhǎng)組長(zhǎng)6油層組進(jìn)行小層精細(xì)劃分,為頂面構(gòu)造特征分析、沉積相展布以及油藏分析等提供準(zhǔn)確的地層研究單元。研究表明,長(zhǎng)6油層組各小層頂面構(gòu)造形態(tài)整體表現(xiàn)為西傾斜坡,構(gòu)造傾角不到1°,平均坡降3-4m/km,且在中西部的唐231～唐176井區(qū)發(fā)育一個(gè)形態(tài)完整的北東-南西走向的背斜構(gòu)造,各小層之間的構(gòu)造形態(tài)具有較強(qiáng)繼承性。通過張羅溝區(qū)沉積微相研究顯示,長(zhǎng)6油層組沉積體系類型為一套水退背景下建設(shè)型三角洲前緣沉積,微相類型以水下分流河道及分流間灣為主。水下分流河道為油氣富集提供了有利的儲(chǔ)集空間,分流間灣泥巖及粉砂質(zhì)泥巖既可作為油氣側(cè)向遮擋,也可作為直接蓋層,為研究區(qū)長(zhǎng)6油藏的油氣富集提供很好的遮擋和保存條件。長(zhǎng)6儲(chǔ)層砂巖巖石類型為長(zhǎng)石砂巖,碎屑顆粒磨圓度以次圓～次棱角狀為主,分選程度為中～好,物性條件相對(duì)較差,屬低～特低孔、特低～超低滲儲(chǔ)層,但各小層之間的儲(chǔ)層物性相差不大,總體受沉積和砂體展布控制,孔隙度、滲透率分布區(qū)間相對(duì)較均勻,在一定的壓裂條件下,可以改善物性條件,仍可獲得很好的產(chǎn)能。結(jié)合甘谷驛油田的儲(chǔ)層劃分標(biāo)準(zhǔn),綜合評(píng)價(jià)認(rèn)為張羅溝區(qū)長(zhǎng)6儲(chǔ)層類型為Ⅱ、Ⅲ類,具備一定的儲(chǔ)集能力,為有效儲(chǔ)層,屬中等～較好類別儲(chǔ)層。延長(zhǎng)組成熟的烴源巖、長(zhǎng)6油層組三角洲前緣復(fù)合河道砂體、疊置連片砂層及微裂隙形成的有利通道、巖性圈閉形成時(shí)期與有利排烴期的有機(jī)配置等因素的共同作用,使甘谷驛油田張羅溝區(qū)具備了有利的油氣成藏條件,油藏類型為巖性油藏,油水混儲(chǔ),無明顯邊、底水,其分布主要受水下分流河道砂體物性控制,油藏埋深總體為東淺西深。
[Abstract]:Ganguyi Oilfield is located at the junction of Baota District and Yanchang County, Yan'an City, Shaanxi Province. the tectonic position is located in the southeast of the secondary tectonic unit of Ordos Basin-the northern slope of Shaanxi, and the regional geological activity is weak. The Yanchang 6 formation of Triassic is the most important reservoir-bearing system in this oil field. The Chang6 reservoir is characterized by low mineral maturity and high structural maturity, and the reservoir has the characteristics of low porosity, low permeability and low oil saturation. There are many previous studies on sedimentary facies and reservoir characteristics in other areas of Ganguyi Oilfield, but the scientific research work in Zhangluogou area is relatively weak and the degree of basic geological research is low. Therefore, the in-depth study of sedimentary items and reservoir characteristics in this area can provide the basis for the calculation of reserves and the compilation and development of reserves in this area. On the basis of regional formation correlation, combined with drilling and logging data, the small layer fine division of Yanchang 6 reservoir group is carried out in this paper, which provides an accurate formation research unit for the analysis of top structural characteristics, sedimentary phase distribution and reservoir analysis. The results show that the structural morphology of the top surface of each small layer of Chang6 reservoir is westward inclined slope, with a structural dip angle of less than 1 擄and an average slope drop of 3-4 m 鈮，

本文編號(hào)：2493000