牛圈湖砂岩油藏重复压裂技术研究与应用

牛圈湖西山窑砂岩油藏属于典型的"低压、低孔、特低渗"三低砂岩油藏,一次改造储量动用程度低,采收率低。为提高牛圈湖砂岩油藏储量动用率及最终采收率,亟需探索非常规砂岩油藏重复压裂技术对策,"储层精细改造"技术思路和技术配套显得尤为重要。针对上述难题,通过优化牛圈湖油田西山窑油藏配套压裂技术、开展体积压裂、暂堵压裂技术试验,增产效果显著,取得了较好的经济效益,为同类油藏的开发提供了强有力的技术保障。     

牛圈湖“三低”砂岩油藏配套压裂技术研究与应用

牛圈湖油田西山窑油藏具有低孔、特低渗以及低温、低压特征,单井自然产能极低,绝大多数油井都需经过压裂改造才能获得高产。根据油藏特征,分析了压裂改造技术的难点:压裂液破胶返排困难、要求裂缝高导流能力及适当控制缝高延伸。针对上述难题,研究形成了牛圈湖油田西山窑油藏配套压裂技术、压裂投产一体化管柱技术及高砂比压裂技术。该压裂增产技术应用于牛圈湖油田,增产效果显著,取得了较好的经济效益,为同类油藏的开发提供了强有力的技术保障。     

水力喷射压裂技术在七棵树油田的应用

水力喷射压裂是集射孔、压裂、隔离一体化的新型增产改造技术,适用于低渗透油藏直井、水平井的增产改造,是低渗透油藏压裂增产的一种有效方法。为了提高特低渗储量的动用程度和单井日产水平,七棵树油田进行水平井开发试验,采用水力喷射分段压裂技术,大幅提高了单井产能,取得了良好的增产效果。     

低渗透油藏水平井分段压裂改造技术研究与应用

低渗透油藏具有孔隙度、低渗透率、低储量丰度“三低”特征,实施水平井开发自然产能低,需要进行储层压裂改造才能获得较高产能,因此水平井完井方式、井身结构、射孔参数等均需要与分段压裂改造工艺相匹配,才能实现低渗透储量有效动用。本文以J区块为例,对水平井完井方式、油井套管尺寸及类型、射孔方式及参数、水平井压裂改造工艺技术等开展研究,现场应用25口井,平均单井初期日产油20 t,阶段累产油1.2万t,取得较好生产效果,所取得成果和认识可为同类型油藏提供借鉴经验。     

超前注水在七棵树油田SW10区块水平井开发的应用

七棵树油田属于典型的低压、特低渗油藏。为了提高开发效果,七棵树油田SW10区块对水平井的开发采用了超前注水,根据开发理论与生产实践,对七棵树油田SW10区块的超前注水开发效果做了分析。结果表明:超前注水对SW10区块水平井压裂效果、含水率和产量自然递减产生了明显影响。超前注水后,地层压力高,压裂液返排率提高,排液期缩短,有效提高了投产初期的产油量;减小了地层压力下降造成的储层物性伤害,有效提高了原油相对渗透率,降低了水平井的含水率;采用超前注水的油井比同步注水的油井的地层压力保持水平高,地层压力下降相对缓慢,单井产量递减慢。     

低渗透扶余油层缝网压裂技术探索及应用

针对大庆外围S油田低渗透扶余油层储层物性差,注水受效差,为改善注水开发效果,提高单井产量,在该油田开展缝网压裂试验,并与常规压裂效果进行对比,探索低渗透扶余油层有效动用方式,同时为同类型油藏的经济有效开发提供技术手段。     

低压低渗超低流度油藏解堵技术研究与应用

三塘湖油田牛圈湖区块西山窑油藏属于低压、低渗、超低流度的低温砂岩油藏,油藏非均质性严重,原始地层压力系数低,原油粘度高,在开采过程中,原油乳化严重,乳化后粘度大幅上升。本文介绍了热化学复合解堵机理、酸化工作液配方、解堵工艺技术和矿场应用效果。矿场试验应用结果表明,热化学复合解堵工艺技术对解除油层有机和无机堵塞、降低原油粘度具有良好效果,可大幅提高油井的供液能力,成为超低流度油藏增产的一项新工艺。2011年牛圈湖西山窑油藏应用热化学复合解堵14口井,平均单井日增油量3.1t,动液面平均上升406m,平均单井有效生产期达到80天以上,平均单井累计增油量超过250t。     

牛圈湖油田西山窑组“三低”复杂砂岩油藏测井解释及应用

牛圈湖油田位于三塘湖盆地马朗凹陷西北部,其目的层为中侏罗统西山窑Ⅱ砂组,牛圈湖西山窑组油藏属于岩性控制的“三低”砂岩油藏。结合实际生产情况,制定了测井解释图版,对255口井进行了二次解释,解释符合率超过85%,全区共解释有效层764层,提取有效厚度2190.59m,其中北区1017.53m,东区726.44m,南区446.62m。为下步有效动用开发提供了可靠的地质依据。     

安83致密油藏水平井开发技术政策探讨

胡尖山油田安83擞密油藏地质储量1．4亿吨,储量规模大,但是油藏物性差,难动用。从2010年开始试验开发,通过定向井开发暴露出单井产量低的问题,从2011年实施水五点与七点水平井开发,水平井与定向井对比初期产量高,递减小,同时也出现水平井见水问题,2012年进行优化水平井井网,开展扩大井排距试验和自然能量开发试验。试验效果较好,初期平均单井产量突破10吨。     

低渗透油田水平井多段压裂试验与应用

大庆外围低渗油田储层渗透率低,丰度低,厚度薄,直井开发效益差。水平井压裂开发是一种提高低、特低渗透油气藏难动用储量的有效开发手段。朝阳沟油田早期开展过水平井全井限流法压裂试验,但水平井全井限流法压裂存在针对性差,部分储层压不开及小层规模难以控制等问题。为提高水平井压裂的针对性和压裂效果,在低渗透油田某区块开展了水平井多段压裂技术试验,探索提高特低渗透储层单井产量的有效技术手段,为特低渗透难采储量经济有效动用开辟新途径。     

Laboratory Studies to Determine Suitable Chemicals to Improve Oil Recovery from Garzan Oil Field

Garzan oil field is located at the south east of Turkey. It is a mature oil field and the reservoir is fractured carbonate reservoir. After producing about 1% original oil in place (OOIP) reservoir pressure started to decline. Waterflooding was started in order to support reservoir pressure and also to enhance oil production in 1960. Waterflooding improved the oil recovery but after years of flooding water breakthrough at the production wells was observed. This increased the water/oil ratio at the production wells. In order to enhance oil recovery again different techniques were investigated. Chemical enhanced oil recovery (EOR) methods are gaining attention all over the world for oil recovery. Surfactant injection is an effective way for interfacial tension (IFT) reduction and wettability reversal. In this study, 31 different types of chemicals were studied to specify the effects on oil production. This paper presents solubility of surfactants in brine, IFT and contact angle measurements, imbibition tests, and lastly core flooding experiments. Most of the chemicals were incompatible with Garzan formation water, which has high divalent ion concentration. In this case, the usage of 2-propanol as co-surfactant yielded successful results for stability of the selected chemical solutions. The results of the wettability test indicated that both tested cationic and anionic surfactants altered the wettability of the carbonate rock from oil-wet to intermediate-wet. The maximum oil recovery by imbibition test was reached when core was exposed 1-ethly ionic liquid after imbibition in formation water. Also, after core flooding test, it is concluded that considerable amount of oil can be recovered from Garzan reservoir by waterflooding alone if adverse effects of natural fractures could be eliminated.     

Emerging applications of nanomaterials in chemical enhanced oil recovery:Progress and perspective

In enhanced oil recovery, different chemical methods utilization improves hydrocarbon recovery due to their fascinating abilities to alter some critical parameters in porous media, such as mobility control, the interaction between fluid to fluid, and fluid to rock surface. For decades the use of surfactant and polymer flooding has been used as tertiary recovery methods. In the current research, the inclusion of nanomaterials in enhanced oil recovery injection fluids solely or in the presence of other chemicals has got colossal interest. The emphasis of this review is on the applicability of nanofluids in the chemical enhanced oil recovery. The responsible mechanisms are an increment in the viscosity of injection fluid, decrement in oil viscosity, reduction in interfacial and surface tension, and alteration of wettability in the rock formation. In this review, important parameters are presented,which may affect the desired behavior of nanoparticles, and the drawbacks of nanofluid and polymer flooding and the need for a combination of nanoparticles with the polymer are discussed. Due to the lack of literature in defining the mechanism of nanofluid in a reservoir, this paper covers majorly all the previous work done on the application of nanoparticles in chemical enhanced oil recovery at home conditions. Finally, the problems associated with the nano-enhanced oil recovery are outlined, and the research gap is identified, which must be addressed to implement polymeric nanofluids in chemical enhanced oil recovery.     

崖城13-1气田高温低压修井液类型选择

针对高产开采10多年的崖城13—1气田出现的地层压力持续下降、单井产量持续降低、产液量和水（液）气比总体上升、气井水淹等现状,在调研了大量国内外高温低压油气藏修井液体系类型及应用情况扣国内外低密度钻井液体系研究现状以及应用情况的基础上,结合崖城13—1气田高温（气藏中部温度达176℃）低压（地层压力系数部分低至0．17）和储层非均质性强（渗透率2．2～1604mD）的特征,选择适合其储层特征的修井液类型为暂堵型修井液,为崖城13—1气田高温低压井的稳产增产改造和高效开发提供了技术保障。     

Surfactant Enhanced Oil Recovery in a High Temperature and High Salinity Carbonate Reservoir

The goal of this work was to find an effective surfactant system for enhanced oil recovery after water injection substituting for oil at a vuggy fractured reservoir with a high temperature and high salinity (220,000 mg/L). Four types of surfactants with concentrations (less than 0.2 %) were screened. Washing oil experiments were conducted in Amott cells. A surfactant system was established by mixing a surfactant with best ultimate recovery and one with best recovery rate. The optimized surfactant system could recover 50 % of remaining oil. To study the mechanism of enhanced oil recovery after water injection substituting oil, interfacial tension (IFT) and contact angle were measured. Experimental results showed that surfactants with good washing ability had low IFT, but surfactants with low IFT may not have a good washing ability. IFT had no obvious relationship with the increased oil recovery or washing ability. The optimized system could not alter carbonate to decrease the oil‐wetting capability. Though octadecyl trimethyl ammonium chloride had a good ability wet the carbonate with water, it could not recover much oil. Therefore, except for interfacial tension and wettability alteration, there must be other parameters dominating oil recovery after water injection substituting for oil.     

Emerging applications of nanomaterials in chemical enhanced oil recovery: Progress and perspective

In enhanced oil recovery, different chemical methods utilization improves hydrocarbon recovery due to their fascinating abilities to alter some critical parameters in porous media, such as mobility control, the interaction between fluid to fluid, and fluid to rock surface. For decades the use of surfactant and polymer flooding has been used as tertiary recovery methods. In the current research, the inclusion of nanomaterials in enhanced oil recovery injection fluids solely or in the presence of other chemicals has got colossal interest. The emphasis of this review is on the applicability of nanofluids in the chemical enhanced oil recovery. The responsible mechanisms are an increment in the viscosity of injection fluid, decrement in oil viscosity, reduction in interfacial and surface tension, and alteration of wettability in the rock formation. In this review, important parameters are presented, which may affect the desired behavior of nanoparticles, and the drawbacks of nanofluid and polymer flooding and the need for a combination of nanoparticles with the polymer are discussed. Due to the lack of literature in defining the mechanism of nanofluid in a reservoir, this paper covers majorly all the previous work done on the application of nanoparticles in chemical enhanced oil recovery at home conditions. Finally, the problems associated with the nano-enhanced oil recovery are outlined, and the research gap is identified, which must be addressed to implement polymeric nanofluids in chemical enhanced oil recovery.     

微生物技术在油气田开发中的研究与应用进展

综述了微生物技术在油气勘探、渗透率调剖、提高采收率、清防蜡、原油破乳、浮油处理方面的应用,并对难点问题进行了分析,展望了微生物技术在油气田开发中的应用前景.     

关于注CO_2井井筒温度场的模型研究

注二氧化碳提高采收率是一种很具潜力的增油措施,在注入二氧化碳的过程中由于地层和井筒内存在温差,热量会由地层向井筒内传递。主要以注二氧化碳井筒温度场计算模型-注二氧化碳井井筒瞬态温度-压力耦合模型的演变方式为研究目标。     

木素及衍生物在油田上的应用

木素磺酸盐及改性物在三次采油过程中，具有降低石油磺酸盐等阴离子型活性剂在岩石表面上的吸附损失、乳化原油，与石油磺酸盐产生协同效应，降低油、水界面张力，提高残余油回收效率的性能。介绍了木素碘酸盐的改性方法与用途。应用木素磺酸盐及改性物进行三次采油，对于有效地开采水驱残余油，降低表面活性剂驱油成本具有重要意义。     

Superior enhancement of imbibition recovery by novel surfactant mixtures with a large hydrophobic group combined with nanosilica

Low interfacial tension (IFT) drainage and imbibition are effective methods for improving oil recovery from reservoirs that have low levels of oil or are tight (i.e., exhibit low oil permeability). It is critical to prepare a high efficient imbibition formula. In this work, a novel 2,4,6-tris(1-phenylethyl)phenoxy polyoxyethylene ether hydroxypropyl sodium sulfonate (TPHS) surfactant was synthesized and evaluated for imbibition. Its structure was confirmed by Fourier transform infrared spectroscopy and the interfacial tension (IFT) of the crude oil/0.07% TPHS solution was 0.276 mN/m. When 0.1 wt% TPHS was mixed with 0.2 wt% alpha olefin sulfonate (AOS), the IFT was lowered to 6 × 10⁻² mN/m. The synergy between nanoparticles (NPs) and TPHS/AOS mixed surfactant was studied by IFT, contact angle on sandstone substrates, zeta potential, and spreading dynamics through microscopic methods. The results show that the surfactant likely adsorbs to the NP surface and that NP addition can help the surfactant desorb crude oil from the glass surface. With the addition of 0.05 wt% SiO₂ NPs (SNPs), the imbibition oil recovery rate increased dramatically from 0.32%/h to 0.87%/h. The spontaneous imbibition recovery increased by 4.47% for original oil in place (OOIP). Compared to flooding by TPHS/AOS surfactant solutions, the oil recovery of forced imbibition in the sand-pack increased by 12.7% OOIP, and the water breakthrough time was delayed by 0.13 pore volumes (PV) when 0.05% SNPs were added. This paper paves the way for enhanced oil recovery in low-permeability sandstone reservoirs using novel TPHS/AOS surfactants and SNPs.     

影响低渗透油藏空气泡沫驱的多参数综合评价

根据敖南油田M区块的开发特征,对比分析了各种改善低渗透油藏开发效果的提高采收率方法优缺点,开展了M区块高含水期的空气泡沫驱技术研究。针对现场应用参数存在一定的不确定性,缺乏参数定量值等问题,本文运用数值模拟软件对对比方案进行预测,首次以增油量和投入产出比作为评价指标,对敖南油田M区块空气泡沫驱注入参数进行优化评价。研究结果表明,对于敖南油田,注空气效果影响因素的重要性大小依次为气液比起泡剂浓度注气速度≈起泡剂注入量。注入参数最优方案为气液比为3:1;起泡剂浓度为0.3%;注气速度为40 m~3/d;起泡剂注入量为0.5 PV。对敖南油田空气泡沫驱提高采收率开发方案的制订及优化具有重要指导意义。