塔河12区超深、超稠油油藏评价及开发技术研究

【作者】 李新华；

【导师】 张烈辉； 陈惠超；

【作者基本信息】 西南石油大学 ， 石油与天然气工程， 2009， 硕士

【摘要】 塔河油田12区奥陶系油藏属于超深岩溶缝洞型油藏,油藏埋深大,非均质性严重,原油重质高粘,属于超稠油油藏,油藏开发难度极大,这类油藏国内外无经验可循。2007年12区的AD4、AD7、S94CH井相继获得高产工业油气流,且AD4井最高日产达千吨,已成为“十一五”期间西北油田分公司增储上产的重点区域。本论文综合运用多种方法技术,从寻找控制油气产能及油气分布的主要地质因素出发,研究12区奥陶系油藏的勘探开发地质特点,查清缝洞型储层的地质特征、发育规律及控制因素;研究油藏的产能、油气水分布规律;同时研究12区开发动态特征和超稠油油藏物性特征,探索超稠油油藏的合理开发方式及高效开采工艺技术,为合理高效开发提供理论依据和技术支撑。通过本文研究,得出如下结论及认识:1、12区断裂较发育,既是油气运移的主要通道,又是形成遮挡的必要条件。研究区内发育的F2、F3、F4这3条主断裂控制了12区的构造格局:西部构造低洼区、中部构造斜坡和构造高地,控制了12区的岩溶缝洞储集体沿断裂的发育方向和油气的运移。2、12区奥陶系发育加里东中期三幕岩溶作用、海西早期和海西晚期岩溶作用,其中海西早期岩溶强度大、大型岩溶洞穴发育,主要受古地貌和断裂控制。3、12区岩溶储集体东部易充填、中部最发育、西部欠发育。12区总体处于岩溶高地(东部)—岩溶斜坡区(中—西部)。具明显的东高、西低的特征,东侧为岩溶高地,西侧为岩溶盆地,其间为岩溶斜坡。岩溶最为发育且保留机率较高的是岩溶斜坡,特别是岩溶缓坡及其上的次级岩溶残丘,它是寻找岩溶型储层的最佳地区;其次是岩溶高地及岩溶谷地近岩溶斜坡一侧。4、12区油气富集主要在中部的S99-TK1207、AD4-AD7、TK1231-AD15、缝洞带,东部的TK1243-TK1210、TK1204-TK1229缝洞带。5、12区油水关系主要受断裂控制,东部水体发育,中部油气富集,西部水体局部发育。6、形成了12区超深、超稠油油藏的能量补充开发方式综合12区油藏地质、开发特征研究和油藏物性特征,参考塔河主体区及国内外其它油田开发方式及技术现状,以追求最大的经济效益和提高最终采收率为目标,表明12区在开发早期利用天然能量开发,针对封闭的定容体则在早期油井停喷后采用单井注水替油,对具有一定天然能量的多井连通单元则在开发早、中期采用注水补充能量的开发方式效果较好。7、形成了12区超深、超稠油油藏的高效井位部署技术针对塔河油田12区超深、超稠缝洞型油藏特点,以“整体部署、层次开发、动态调整”的开发技术思路,形成了上奥陶剥蚀区评价新缝洞带、打构造、岩溶高部位、有利地震反射特征;覆盖区找高产缝洞带、打最有利反射特征,沿断裂带线状布井,外扩、加密能量充足缝洞带、评价新缝洞带的高效井位部署技术。8、通过对12区稠油井筒温度、压力的敏感性研究表明:温度是影响该区原油粘度的最主要因素,压力对稠油粘度的影响不敏感;9、通过对掺稀降粘、化学降粘、电加热降粘、闭式热流体循环加热降粘等工艺的研究论证,认为掺稀降粘、化学降粘工艺适合塔河十二区超稠油开采的需要,其中掺稀降粘是主导工艺,电加热降粘、闭式热流体循环加热降粘工艺目前适应性较差。10、形成了超深、超稠油举升工艺技术①大管径采油工艺技术②掺稀降粘工艺技术③电潜泵开采工艺技术④流动改性剂工艺技术⑤油溶性化学降粘工艺技术更多还原

【Abstract】 The Ordovician reservoir in Tahe field 12^th block is supper-deep karst aperture-cave reservoir. This reservoir is of great burying depth, intensity heterogeneity, which is filled with heavy crude with high viscosity. It is extremely difficult to develop this kind of reservoir, and there is no successful experience to follow. In 2007, wells in the 12^th block like AD4, AD7, and S94CH in the 12^th block have successively obtained high commercial production, especially the highest daily output of S94CH ever reached to 1000 ton. Such block has been the key district to increase reserve and production for northwest branch of Sinopec during the eleventh five-year plan.In this paper, starting from finding the geological factors which control productivity and distribution of gas and oil, we have studied geological characteristics for exploration and development in the 12^th block Ordovician reservoir through synthetically applying many kinds of methods and technologies to make clear the geological characteristics, development law and controlling factors of fracture-cavity reservoirs. Reservoir productivity and distribution of gas and oil have been studied. Meanwhile, we studied development performance characteristics and property characteristics of supper-heavy oil reservoir, quested the reasonable development mode and efficient development process technology of supper-heavy oil reservoir. Based on these work, theoretical basis and technology support for reasonable development have been provided.Based on the study in this thesis, we achieved following conclusions and recognition:1. The 12th region was rich with faults, which is not only the channel of gas and oil but also the essential condition of sealing gas and oil.The three faults in the study region, F2, F3 and F4, dominate the structural framework in the 12th region: the low laying structure in west, the structure slop and structure high dominant the distribution direction of karst aperture-cave reservoir and the migration of gas and oil.2. The Ordovician reservoir in 12th region undergo karst process of the three stages of the middle Caledonian, the early and late stage of early hercynian, while karst process is of great intensity and large scale cavities are developed in this stage, which are mainly controlled by ancient landform and faults.3. Karst aperture-cave reservoir in east of the 12th region is easy to be filled, while the middle is of good property and the west worse.On the whole, the 12th region is in highland and slope of karst region, which are relatively in east and middle-west. It is obviously that the east is higher than the west, since the east is karst highland and the west is karst basin with karst slope between them. On the slope region, karstification is obviously and it is more probable to be remained of this effect, especially on the slight slope or secondary karst hammock on the slope. These regions are the best choice to find karst reservoir, and secondly the karst highland and regions of karst valley near the karst slope.4. Gas and oil are enriched in east fracture-cavity zones like S99-TK1207, AD4-AD7, TK1231-AD15 and in west fracture-cavity zones like TK1243-TK1210, TK1204-TK1229.5. The relationship of gas and oil in the 12th region are controlled by faults, which results that it is rich in water in the east, rich in gas and oil in west, rich in water in partial areas of the west.6. Energy complement development mode of supper-deep and supper-heavy oil reservoir has been formed.Comprehensively study reservoir geology research, development characteristics research, reservoir property characteristics and reference the field development mode and technical status of main region in Tahe field and other fields in abroad, according to the aim of chasing largest economic efficiency and improving the final recovery, it is suggested that natural energy plays the role in the early development stage and it is of good effect to apply the development mode of single-well water injection substituting oil after ceasing flush in the early stage for closed constant-volume system, also it is of good effect for muti-well unit with certain natural energy to apply the development mode of complement energy by injection water at the early and middle development stage.7. Efficient well net deployment technique for the supper-deep and supper-heavy reservoir in the 12th region has been achieved.In view of the characteristics of the supper-deep and supper-heavy reservoir in the 12th region of Tahe field, according to integral deployment, hierarchy development and dynamic adjustment, we has formed a set of efficient well deployment techniques. For the denudation area of upper Ordovician, we should evaluate new fracture-cavity zone, deploy wells on high part of structure and karst zone as well as sites with preferential characteristic of seismic reflection. For coverage area, we should search high production fracture-cavity zone, deploy wells on sites with the most preferential characteristic of seismic reflection, deploy wells in a line along fracture zone, expend and infill those fracture-cavities with sufficient energy, evaluate new fracture-cavity zone.8. Through studying sensibility of wellbore temperature and pressure in the 12th region, it is suggested that temperature is the main factor affecting the oil viscosity in this region while pressure is insignificant factor to viscosity of heavy oil.9. Through systematic study on those viscosity reduction process technology such as blending light dropping viscosity, chemical methods, heated by electricity, heated by closed heat flux in recycling and so on, it is concluded that blending light and chemical viscosity reduction process satisfy the needs of heavy oil development in the 12^th region, especially process of blending light dropping viscosity holds a dominant position. However, those like heated by electricity, heated by closed heat flux in recycling are of worse feasibility at present.10. Lifting process technology in supper-deep supper-heavy oil wells has been formed.①large diameter pipe process technology for oil production②blending light dropping viscosity process technology③electric submersible pump process technology④flow modification process technology⑤oil-soluble chemical viscosity reduction process technology更多还原