红山油田的红003井区坐落于准噶尔盆地的西北边缘。以往研究普遍将该区域侏罗系齐古组二段的油层有效下限电阻率定为25 Ω·m。然而,近期hD91445井在J3q2层的473~480 m井段(电阻率20 Ω·m)进行的射孔及随后的注汽抽油试验产出了204吨原油,日产油率为1.4吨/日,油气比为0.28,这一结果突破了先前对油层有效性下限的理解,表明齐古组油层下限值得进一步研究。鉴于此,本研究旨在深入探讨齐古组二段的油层下限。通过综合钻井取心、测井、录井和分析化验资料,以及考量86口井在该层段的试油、试采和生产数据,本论文对齐古组二段的油层下限进行了重新界定。研究发现红003井区齐古组二段主要由细至中粒砂岩构成,储集空间以剩余粒间孔(55.5%)和原生粒间孔(42.5%)为主,辅以少量粒内溶孔(2%)。这一区域以29%的平均孔隙度和756.4 mD的平均渗透率表现出高孔隙度和高渗透率的优质储层条件。此外,通过本研究,油层的电阻率下限被修正为11.5 Ω·m,有效孔隙度下限调整为20.5%,含油饱和度下限调整为50%,这些关键参数的调整突破了原有的界定。基于这些新的认识,对该研究区地质储量的重新计算显示,相较于原储量报告,地质储量增加了67.6 × 104吨。这一成果不仅为深化储层理解提供了新的视角,也为未来的储量资源勘探和开发提供了重要依据。 The Red 003 well area in the Hongshan Oilfield is located at the northwest edge of the Junggar Basin. Previous studies have generally set the effective lower reservoir resistivity limit of the second section of the Jurassic Qigu Formation in this area at 25 Ω·m. However, the recent perforation and subsequent steam injection and pumping test of the hD91445 well in the J3q2layer in the 473~480 m section (resistivity 20 Ω·m) produced 204 tons of crude oil at a daily oil production rate of 1.4 tons per day, with an oil/gas ratio of 0.28, which breaks through the previous understanding of the lower limit of oil formation effectiveness, suggesting that it is worth further study. This result breaks through the previous understanding of the lower limit of oil formation effectiveness and suggests that the lower limit of oil formation in the Qigu Formation deserves further study. In view of this, this study aims to deeply explore the lower limit of oil formation in the second section of the Qigu Formation. By synthesizing the drilling core, logging, recording and analytical assay data, as well as considering the oil test, recovery test and production data of 86 wells in this section of the formation, this thesis redefines the lower limit of the oil formation in the second section of the Qigu Formation. It is found that the second section of the Qigu Formation in the Hong003 well area is mainly composed of fine- to medium-grained sandstones, and the reservoir space is dominated by remaining intergranular pores (55.5%) and primary intergranular pores (42.5%), supplemented by a small number of intragranular soluble pores (2%). This area exhibits high-quality reservoir conditions of high porosity and high permeability with an average porosity of 29% and an average permeability of 756.4 mD. In addition, through this study, the lower limit of resistivity of the reservoir was revised to 11.5 Ω·m, the lower limit of effective porosity was adjusted to 20.5%, and the lower limit of oil saturation was adjusted to 50%, and the adjustments of these key parameters broke through the original definitions. Based on these new understandings, the recalculation of the geological reserves in the study area shows that the geological reserves have increased by 67.6 × 104t compared with the original reserves report. This result not only provides a new perspective for deepening the reservoir understanding, but also provides an important basis for future exploration and development of reserve resources.
红山油田的红003井区坐落于准噶尔盆地的西北边缘。以往研究普遍将该区域侏罗系齐古组二段的油层有效下限电阻率定为25 Ω·m。然而,近期hD91445井在J3q2层的473~480 m井段(电阻率20 Ω·m)进行的射孔及随后的注汽抽油试验产出了204吨原油,日产油率为1.4吨/日,油气比为0.28,这一结果突破了先前对油层有效性下限的理解,表明齐古组油层下限值得进一步研究。鉴于此,本研究旨在深入探讨齐古组二段的油层下限。通过综合钻井取心、测井、录井和分析化验资料,以及考量86口井在该层段的试油、试采和生产数据,本论文对齐古组二段的油层下限进行了重新界定。研究发现红003井区齐古组二段主要由细至中粒砂岩构成,储集空间以剩余粒间孔(55.5%)和原生粒间孔(42.5%)为主,辅以少量粒内溶孔(2%)。这一区域以29%的平均孔隙度和756.4 mD的平均渗透率表现出高孔隙度和高渗透率的优质储层条件。此外,通过本研究,油层的电阻率下限被修正为11.5 Ω·m,有效孔隙度下限调整为20.5%,含油饱和度下限调整为50%,这些关键参数的调整突破了原有的界定。基于这些新的认识,对该研究区地质储量的重新计算显示,相较于原储量报告,地质储量增加了67.6 × 104吨。这一成果不仅为深化储层理解提供了新的视角,也为未来的储量资源勘探和开发提供了重要依据。
红山油田,红003井区,侏罗系齐古组二段,储层特征
Jiaming He, Yanfei Kou
School of Earth Sciences, Guilin University of Technology, Guilin Guangxi
Received: Jan. 12th, 2024; accepted: Mar. 20th, 2024; published: Mar. 27th, 2024
The Red 003 well area in the Hongshan Oilfield is located at the northwest edge of the Junggar Basin. Previous studies have generally set the effective lower reservoir resistivity limit of the second section of the Jurassic Qigu Formation in this area at 25 Ω·m. However, the recent perforation and subsequent steam injection and pumping test of the hD91445 well in the J3q2layer in the 473~480 m section (resistivity 20 Ω·m) produced 204 tons of crude oil at a daily oil production rate of 1.4 tons per day, with an oil/gas ratio of 0.28, which breaks through the previous understanding of the lower limit of oil formation effectiveness, suggesting that it is worth further study. This result breaks through the previous understanding of the lower limit of oil formation effectiveness and suggests that the lower limit of oil formation in the Qigu Formation deserves further study. In view of this, this study aims to deeply explore the lower limit of oil formation in the second section of the Qigu Formation. By synthesizing the drilling core, logging, recording and analytical assay data, as well as considering the oil test, recovery test and production data of 86 wells in this section of the formation, this thesis redefines the lower limit of the oil formation in the second section of the Qigu Formation. It is found that the second section of the Qigu Formation in the Hong003 well area is mainly composed of fine- to medium-grained sandstones, and the reservoir space is dominated by remaining intergranular pores (55.5%) and primary intergranular pores (42.5%), supplemented by a small number of intragranular soluble pores (2%). This area exhibits high-quality reservoir conditions of high porosity and high permeability with an average porosity of 29% and an average permeability of 756.4 mD. In addition, through this study, the lower limit of resistivity of the reservoir was revised to 11.5 Ω·m, the lower limit of effective porosity was adjusted to 20.5%, and the lower limit of oil saturation was adjusted to 50%, and the adjustments of these key parameters broke through the original definitions. Based on these new understandings, the recalculation of the geological reserves in the study area shows that the geological reserves have increased by 67.6 × 104t compared with the original reserves report. This result not only provides a new perspective for deepening the reservoir understanding, but also provides an important basis for future exploration and development of reserve resources.
Keywords:Hongshan Oilfield, Hong003 Well Area, Jurassic Qigu Formation II, Reservoir Characterization
Copyright © 2024 by author(s) and beplay安卓登录
This work is licensed under the Creative Commons Attribution International License (CC BY 4.0).
http://creativecommons.org/licenses/by/4.0/
油层物性的界定是油田开发的基石,其中包括孔隙度和渗透率这两个关键参数,它们决定了油层是否能有效储存和渗滤流体 [
红山油田位于准噶尔盆地西北缘红车断裂带北段,距克拉玛依市西南约20 km,面积100.1 km2。该井区油藏东北与红浅稠油开发区相邻,与红山嘴稀油区油藏紧密相接且部分重叠 [
鉴于此,本研究利用hD91445井的岩芯分析、试油结果和测井数据,对J3q2层的有效孔隙度、有效渗透率以及含油饱和度的下限值进行了重新厘定。研究发现,这些物性参数的下限值均有所降低,从而揭示了原先未被识别的石油地质储量,新增了67.6 × 104吨的地质储量。这一发现不仅为红山油田工区的油藏精细描述和剩余油分布预测提供了更加可靠的依据,而且对于该区块的储集层评价和开发生产策略制定具有重要的指导意义。
油层物性下限一般是以能够储集和渗滤流体的最小孔隙度和最小渗透率来度量的。通常,以相对可靠的试油资料为依据 [
图1. 齐古组J3q2沉积相平面图
红山油田位于准噶尔盆地西北缘红车断裂带北段,距克拉玛依市西南约20 km,面积100.1 km2。研究主要目的层属于早期侏罗系的齐古组,在研究所区西北和中部位于高东南低,为背斜的大型单翼 [
003井区侏罗系齐古组地层厚度81.2 m~138.1 m,平均102.2 m,为一套下粗上细的正旋回沉积。自下而上大致可以将其划分成J3q1、J3q2、J3q3三个砂体组,含油量较高的砂体均已有发育。齐古组属于辨状河沉积,主要发育辫状河道和泛滥盆地亚相和河底滞留、河道、心滩、河道边及河漫滩微相。储层岩性主要为砂岩,其次为砂砾岩和含砾砂岩,胶结程度中等~致密,胶结类型主要为压嵌型为主,孔隙~压嵌型为辅。油层孔隙度变化在20.8%~34.7%之间,平均27.2%,油层渗透率变化在181 mD~4058.8 mD之间,平均676 mD,含油饱和度变化在45.8%~78.3%之间,平均62%。齐古组平均地面原油密度0.965 g/cm3,50℃地面原油粘度3257~13,897 mPa·s,平均6934 mPa·s。其类型是由断层所掩盖和遮挡的带边水与油水过渡带构造成的岩性油藏。如图1。
红003井区齐古组共取心5口井(红074、红083、h91137、h910324、h9065),其中密闭取心2口(红074、h9065),岩心实长102.15 m,含油岩心长94.41 m、岩心观察及粒度、测井资料统计14项124个。
通过综合岩心观察及粒度、测井资料统计可知该区域齐古组的储层岩性主要分别是砂岩(40.2%)、砂砾岩(38.8%),其次是含砾砂岩(3.4%);油层岩性分别是砂岩(67.3%)与含砾砂岩(32.7%)。岩性砂砾岩、含砾砂岩及泥岩均灰绿色,灰色颜色为主。如图2:
图2. h9065井岩心图
根据该地区齐古组二段铸体薄片的资料统计,该地区齐古组二段储层的岩性以细–中砂岩为主。储集的空间种类以残留剩余粒间孔(55.5%)和原生粒间(42.5%)两种形式为主,其次是粒内溶孔和方解石溶孔(2%),储层条件好。孔隙直径1.23~489.86 pm,平均114.32 pm,喉道宽度为1.2~93.6 pm,平均17 pm,面孔率0.0314.49%,平均5.38%,配位数0~4。根据2口大型密闭井式取油中心井(h9023、红077井)的平均含油含水饱和度监测分析统计资料进行统计。主要的两口含油层段的平均含油含水饱和度统计分析数值范围一般为48.7%~75.6%之间,平均含油饱和度分析为60.4%。如图3:
图3. 红003井区齐古组J3q2铸体薄片照片
统计红003井区齐古组二段5口取心井样品,其中储层样品数62块,油层样品数53块,分别建立了该区齐古组二段储层、油层孔渗直方图。从直方图可知,储层孔隙度6.8%~34.8%,平均29.0%,渗透率0.17 mD~1650 mD,平均398.1 mD;油层孔隙度21.9%~34.8%,平均31.1%,渗透率39.6 mD~1650 mD,平均756.4 mD,属于高孔高渗储层,显示了该区较好的储层条件。如图4和图5:
图4. 红003井区齐古组J3q2储层孔渗直方图
图5. 红003井区齐古组J3q2油层孔渗直方图
根据全区齐古组完钻井测井资料,结合该区四性关系研究,将电测曲线响应特征异常点作为标志层与层序界面的识别依据:对全区380口打穿的齐古组井地层进行了精细而统一的分层地层划分,经过垂深矫正后,绘制了红003井区齐古组二段顶面构造图,从构造图中可知,齐古组二段顶面构造的整体形状为西北向东南缓倾的单斜,结合该区东西向地震地质剖面。
经本人研究认为该区齐古组二段沉积相为辫状河三角洲沉积,主要发育水下分流河道微相,砂体受沉积相控制,成西北向东南条带状展布,物源来自西北部,砂体沿河道沉积较厚,向两侧减薄,砂体厚度0~48 m,平均25.5 m。如图6:
图6. 红003井区齐古组J3q2砂体厚度平面图
图7. 过hD917521-红073井齐古组J3q2砂体剖面对比图
图8. 过hD917521-红073井齐古组J3q2砂体平面图
通过该区四性关系研究成果,对该区齐古组二段砂体进行了系统性地解剖。沿河道走向和垂直河道走向“控制性”地绘制了砂体剖面,并结合油井生产情况详细地分析了单砂体平面、剖面展布特征以及砂体对油藏的控制作用,旨在为发现或拓展有利储层提供依据。从沿主河道走向(北西–南东)的两条砂体剖面可知,齐古组二段砂体沿河道方向发育连续稳定。纵向上发育两套砂体:地层中部砂体和底部砂体,其中中部砂体厚度0~35.0 m,平均18.5 m,发育连续稳定且厚度较大,底部砂体厚度0~13.0 m,平均7.0 m,厚度较小。如图7和图8。
图9. 红003井区块侏罗系齐古组油藏密度–孔隙度交会图
图10. 红003井区齐古组二段孔隙度–电阻率交汇图版
根据本区5口取芯井,进行分析化验资料重建骨架图版。制作了红003井区块侏罗系齐古组油藏密度–孔隙度交会图,得出结论 ϕ = 183.11 − 69.28ρ。如图9。
储层含油性与电性相关性较好。含油级别越高,储层含油饱和度越高,其对应的电阻率测井响应值也越高。储层电性能够综合反映储层含油性、岩性、物性。本次在大平房油田同层位油水图版的基础上。根据最新单井电阻率、密度及解释结论统计结果,利用GeoRes软件建立电阻率–孔隙度交会图版。如图10。
截至2022年底,该井累积产油125 t,累积油汽比0.12,周期日产油2.5 t/d,取得了较好的生产效果,hD91727井的试油成功,将电阻率下限由25 Ω·m下降到目前的11.5 Ω·m,下限进一步获得突破,展现了齐古组良好的评价潜力。同时,2019年以来已实施9口齐二低阻井均试获油层,试油成功率100%。如图11。
图11. hD91727井齐古组J3q2层生产曲线
试油的地质贮量往往采用容积法进行计算。所谓的容积法,就是把一块包括油或者含气的表层面积乘以储油层的平均有效厚度,再然后乘以一块储油层的每一块岩石平均有效的孔隙度,就可以得到一块储油或者其他气的平均孔隙 [
石油地质储量的计算(按地面条件下重量计算)。
公制单位计算公式:
N = 100 A h ϕ ( 1 − S w i ) ρ 0 / B o i
式中,N为石油地质储量,万吨;A为含油面积,平方千米;h为平均有效厚度,米; ϕ 为平均有效孔隙度,小数;SWi为油层原始平均含水饱和度,小数; ρ 0 为地面脱气原油密度,吨/立方米; B o i 为原始原油平均体积系数,立方米/立方米。
最终确定J3q2含油面积为1.21 km2。
计算有效厚度采用算的算术平均为11.7 m等值线面积衡权为11.6 m,取算数平均值11.7 m。
计算有效孔隙度采用算的算术平均为28.9%,等值线面积衡权为28.7%,取算数平均值28.9%。
计算含油饱和度采用算的算术平均为54.7%,等值线面积衡权为54.8%,取算术平均值54.7%。
地层原油体积系数:由于本次储量复算未增加PVT资料,沿用原油藏探明储量体积系数1.047。
地面原油密度:根据J3q2井次实际分析值,井点算术平均求得,为0.965。如图12~15:
图12. J3q2含油面积图
图13. J3q2有效厚度等值线图
图14. J3q2孔隙度等值线图
图15. J3q2含油饱和度等值线图
根据上述确定的各项参数,采用容积法进行计算红003井区侏罗系齐古组二段油藏复算原油地质储量为206.3 × 104t,原油技术可采储量为41.3 × 104t,含油面积为1.21 km2。对比原探明含油面积增加了0.20 km2,原油地质储量增加了67.6 × 104t ,原油技术可采储量增加13.6 × 104t。如表1:
类别 | 单元 | 面积 | 有效厚度 | 有效孔隙度 | 含油饱和度 | 地面原油密度 | 体积系数 | 原油地质储量 | 采收率 | 原油可采储量 | |
---|---|---|---|---|---|---|---|---|---|---|---|
区块 | 层位 | km2 | m | % | % | t/m3 | 无因次 | 104t | % | 104t | |
原探明 | 红003井区 | J3q2 | 1.01 | 9.0 | 28.2 | 58.7 | 0.965 | 1.047 | 138.7 | 20 | 27.7 |
复算 | 红003井区 | J3q2 | 1.21 | 11.7 | 28.9 | 54.7 | 0.965 | 1.047 | 206.3 | 20 | 41.3 |
表1. 本次储量复算结果与储量计算结果对比表
1) 齐古组二段顶面构造整体为西北向东南缓倾的单斜,结合该区东西向地震地质剖面,地层倾角3˚~11˚,断裂发育与清水河组具有继承性,断距10~20 m。
2) 齐古组二段砂体沿河道方向发育连续稳定,纵向上发育两套砂体:中部砂体和底部砂体,其中中部砂体厚度0~35.0 m,平均18.5 m,发育连续稳定且厚度较大,底部砂体厚度0~13.0 m,平均7.0 m,厚度较小。
3) 齐古组储层岩性主要为砂岩、砂砾岩,其次为含砾砂岩;油层岩性为砂岩和含砾砂岩。储集空间类型以剩余粒间孔和原生粒间为主,其次为粒内溶孔和方解石溶孔(2%),储层条件好。储层孔隙度平均29.0%,平均398.1 mD;油层孔隙度平均31.1%,渗透率平均756.4 mD,属于高孔高渗储层。
4) 通过开展齐古组二段精细储层展布特征研究,新增9口试采资料,并绘制新的油层图版,结果表明油层电阻率下限由探明的25 Ω·m下降到了11.5 Ω·m,该标准为储层识别及储量研究奠定了基础,为后续老并试油提供了全面的参考依据,同时也为油藏评价、并位部署提供了技术支撑。
何嘉鸣,寇雁菲. 红山油田红003井区齐古组二段储层特征研究Reservoir Characterization of the Second Section of Qigu Formation in Hong003 Well Area of Hongshan Oilfield[J]. 地球科学前沿, 2024, 14(03): 297-312. https://doi.org/10.12677/ag.2024.143028