强封堵油基钻井液体系的研究和应用

基于页岩气井水平段易失稳,油基钻井液漏失将会造成巨大的经济损失,因此水平段对油基钻井液体系的性能要求越来越高。针对以上问题,通过正交试验研制了一种新型的强封堵油基钻井液体系,室内试验证明该体系具有良好的抗污染性、乳化稳定性、失水量低、流变性好、粘度和切力适中。焦页195-1HF井的现场应用和与邻井焦页200-1HF井等数口井的对比,强封堵油基钻井液体系的应用大大降低了漏失风险和漏失成本,节省了11 d的工期,在页岩气开采中具有良好的应用前景。     

低油水比油基钻井液在保页3井的应用

为了解决油基钻井液成本高、钻屑含油量高、后期环保处理难度大等技术难题,加快页岩气的开发进度,缓解油气资源短缺局面,通过室内实验,成功研制出了一套低油水比油基钻井液体系。该体系具有良好的流变性、电稳定性和抑制性,滤失量低,能有效地保护井壁稳定,降低摩阻和扭矩,降低钻井液使用成本。经过在保页3井的应用,满足了现场的施工要求,保证了井下安全。     

涪陵页岩气水平井油基钻井液技术

针对非常规油气藏开发及复杂地层安全钻井的需要,为解决水平井井壁稳定、摩阻、携岩及地层污染问题,开展了油基钻井液技术研究与应用。通过乳化剂、有机土、降滤失剂、封堵剂等处理剂的研选,形成以柴油、白油为基础油的油基钻井液配方、循环损耗量控制技术及现场施工工艺。在涪陵页岩气田应用了100余口井,满足了现场施工需要,取得良好的技术经济效果。结合涪陵区块的具体情况,不断深入研究,2015年研究并现场试验了粉状乳化剂、无土相油基钻井液等新技术。     

北部湾盆地全油基钻井液技术研究与应用

南海西部北部湾海域地质构造复杂,一直以来是钻完井事故的多发区。面对边际油田开发难度的不断增加,针对该海域涠洲组易垮塌、断层多、易井漏、易发生卡钻和储保难度大等特征,通过室内配伍实验,分析各材料加量比例,确定配方,形成了一套新型全油基钻井液体系。通过现场应用表明,与常规油基钻井液对比,全油基钻井液具有更强的封堵能力和抑制性,润滑性能好,抗污染能力强,井眼清洁好,储层保护效果好,有效提高机械钻速,解决了传统强封堵油基钻井液体系出现的诸多问题,达到了综合提速的效果。     

硅酸钾钻井液在页岩气水平井中的可行性研究

页岩气开发以水平井为主,由于页岩地层裂缝与层理发育,在长水平段钻井过程中极易发生垮塌等井眼稳定问题,同时还有携岩、摩阻等一系列问题;大量的研究工作表明,硅酸盐钻井液的抑制性是较为接近油基钻井液体系的,但其能否用于页岩气水平井的钻井过程中是值得探讨的。本文在对硅酸盐钻井液体系及页岩稳定分析的基础上,建立了一套硅酸钾钻井液体系,该钻井液体系除了具有良好的抑制性能以外,更具有较低的滤失量(高温高压滤失量＜6 mL),并且流变性易于控制,润滑性好,分析认为该体系能够满足页岩气水平井钻井的要求。     

甘肃山丹花草滩煤矿扩大区煤炭详查钻井液工艺及应用

在甘肃省山丹县花草滩煤矿扩大区煤炭详查钻探施工中,普遍存在着泥岩地层造浆、膨胀缩径及坍塌掉块等问题。针对上述问题,开展了钻井液工艺研究,选择了有机硅抑制剂、降滤失材料、随钻封堵材料及包被絮凝材料,进行钻井液配方及性能研究。通过室内实验及现场应用,证明了该钻井液具有良好的抑制性能、防塌护壁性能及流变性能,有效解决了上述技术难题,钻井液使用周期大幅提升,显著减少了废弃钻井液的排放,促进了绿色勘查理念在勘查区的实践推广。     

海洋天然气水合物地层钻探钻井液低温流变性能研究

海洋天然气水合物赋存于低温和高压环境条件,以分解抑制法钻进水合物地层,常通过降低钻井液的温度来抑制水合物的分解,所以要求钻井液具有良好的低温性能。对甲酸盐海水钻井液和聚合醇海水钻井液在不同低温条件下的流变性能进行了探讨。结果表明：钻井液处理剂和水合物抑制剂均对钻井液的低温流变性能有不同程度的影响。提出在研究海洋天然气水合物地层钻探钻井液时,应合理选择钻井液体系和处理剂,确保钻井液在低温条件下具有良好的流变性能。     

多功能复合剂在伊塘湖矿区ZK11-1孔的应用

多功能复合剂是一种针对复杂地层钻探研发的新型膨润土有机改性钻井液复合材料。通过敦煌伊塘湖钾镁盐矿区ZK11—1孔的成功应用,证明其具有高效护壁作用,抗盐侵污染能力强,用其配制饱和盐水钻井液可适用于岩盐、钾石盐、光卤石等盐膏地层钻进。     

Hydrologic testing during drilling: application of the flowing fluid electrical conductivity (FFEC) logging method to drilling of a deep borehole

Drilling of a deep borehole does not normally allow for hydrologic testing during the drilling period. It is only done when drilling experiences a large loss (or high return) of drilling fluid due to penetration of a large-transmissivity zone. The paper proposes the possibility of conducting flowing fluid electrical conductivity (FFEC) logging during the drilling period, with negligible impact on the drilling schedule, yet providing important information on depth locations of both high- and low-transmissivity zones and their hydraulic properties. The information can be used to guide downhole fluid sampling and post-drilling detailed testing of the borehole. The method has been applied to the drilling of a 2,500-m borehole at Åre, central Sweden, firstly when the drilling reached 1,600 m, and then when the drilling reached the target depth of 2,500 m. Results unveil eight hydraulically active zones from 300 m down to borehole bottom, with depths determined to within the order of a meter. Further, the first set of data allows the estimation of hydraulic transmissivity values of the six hydraulically conductive zones found from 300 to 1,600 m, which are very low and range over one order of magnitude.     

硬岩破碎地层高温钻孔钻进的钻井液实验研究

针对塔里木盆地某矿区地层倾角大、硬度高、极其破碎,定向钻进钻遇地层含高放射性矿物且温度高,易发生卡埋钻事故及钻孔内高放射性矿物污染钻场环境等问题,选用抗高温具有良好流变力学性能的护孔配浆材料,采用正交实验设计方法,实验研究钻井液配方。优选出耐温达到100℃的不分散低固相聚合物钻井液体系MV-CMC-80A51-NPAN泥浆。该泥浆性能稳定,具有耐温高、失水量低、泥皮簿而致密、剪切稀释性能好、成本低的特点,可使硬岩破碎复杂地层的定向钻进顺利中靶。      

钾铵聚合物钻井液在地热钻井中的应用研究

贵州地热井钻遇地层以灰岩和白云岩为主,夹杂泥岩、砂岩及煤层等不稳定地层,为满足井壁稳定及配合螺杆钻进工艺的需求,确定采用强抑制聚合物钻井液体系。通过正交试验确定了室内配方,并对配方的综合性能进行了室内测评。FT-1与QS-2协同作用可有效改善泥皮质量,白油润滑剂在1%加量时即可将润滑系数降低至0.2以下。其综合性能测试结果表明：该钻井液体系具有良好的流变性,抑制性强且润滑性良好。相比于无固相聚合物钻井液,井眼清洁能力明显增强,机械钻速提高了129%,漏失风险有所下降,取得了良好的实钻效果。     

Application of Greek lignite as an additive for controlling rheological and filtration properties of water–bentonite suspensions at high temperatures: A review

This review paper presents the results of an extensive study investigating whether addition of 3% w/w Greek lignite to 6.42% w/w water–bentonite suspensions, after being exposed to high temperatures, can prevent gelation and control filtration characteristics. Two different bentonites and eight lignites from different Greek basins have been used while a commercial lignite product has been used as standard. The lignite-free bentonite suspensions heated to 177 °C for 16 h (thermal aging) thicken considerably, increasing the yield stress and the yield point. Fluid consistency and flow behavior indices also change while no significant change is observed for plastic viscosity. Thermal aging of the suspensions results in unacceptably high fluid loss values.Addition of Greek lignite to water–bentonite suspensions, followed by thermal aging, provided the rheological stability of the suspensions by maintaining the low yield stress/point regardless of the type of bentonite. Some of the lignites performed as well as their commercial counterpart. No specific trends for rheological improvement have been identified with respect to various characteristics of lignites such as contents of humic, fulvic acids, humins and other parameters such as specific surface area and cation exchange capacity.Furthermore, addition of lignite in most cases provided very good filtration control of the water–bentonite suspensions after exposure to 177 °C, with some Greek lignites being superior to the commercial product. The same lignite parameters examined for rheological control, were also examined to determine their effect on fluid loss of these suspensions for both bentonites. The content of humic and fulvic acids of two groups of lignites showed weak inverse correlations with the fluid loss volumes for both bentonites, while all other parameters did not seem to directly correlate with the effectiveness of the lignites.     

固井冲洗液室内模拟评价方法研究

针对现有固井冲洗液评价方法对于油基钻井液冲洗情况评价存在不足的问题,运用环空壁面与改进装置内筒壁面处剪切速率相等的原理,研究出了一种适用于油基和水基钻井液条件的固井冲洗液室内评价新方法。室内模拟实验分析表明,该方法能更好地反映冲洗液的冲洗效率,并能模拟评价冲洗效率对固井第一或第二界面处胶结的影响情况。该方法操作方便,适用于油基和水基钻井液固井条件。     

涠西南地区岩石特性及钻井液技术研究

北部湾盆地涠西南油田群是南海西部重要的原油产区，同时油田群紧邻众多国家级自然保护区，属于环境敏感区域。针对北部湾盆地涠西南地区环保要求，以及涠洲组和流沙港组钻井过程经常出现井壁失稳导致的憋卡、起下钻阻卡等问题，开展了涠西南地区地层泥页岩特性及环保钻井液技术研究。通过地层岩石黏土矿物分析、孔喉结构分析以及理化性能评价，明确了涠西南地区泥页岩井壁失稳的机理；提出以类油基的水溶性复合基基液为核心，构建了一套具有油基钻井液工程特性和水基钻井液环保特性的新型环保防塌钻井液技术，并进行了相关的现场应用。现场应用显示：应用井与邻井相比，12-1/4″井段阻卡划眼时间减少，井径扩大率大幅度降低，并且在128 h的长时间浸泡过程中没有复杂情况产生，有效地解决了涠洲组、流沙港组易失稳地层的井壁稳定问题；同时，钻井液环保性能达到一级海域环保要求，可以替代目前应用的油基钻井液体系，解决了海上使用油基钻井液存在配制成本高、含油钻屑需全回收及环境危害隐患大等技术难题。该研究对于涠西南油田环保、井壁失稳和钻井液技术发展具有较高的理论价值和借鉴意义。     

环保型弱凝胶护壁护心钻井液研究与应用

海域浅层气地质调查和盐湖环境科学钻探在松散砂岩钻探取样工程中,存在孔壁易坍塌、成孔率低等技术难题,为此开展了松散砂岩地层环保型弱凝胶护壁护心钻井液技术研究。通过弱凝胶结构研究及成胶剂、交联剂及抗盐降滤失剂等材料优选,研发了一套环保型弱凝胶护壁护心钻井液,评价了钻井液的流变性、滤失性、抑制性、护心性能、环保性能等性能,并在山西某盐湖环境科学钻探工程进行现场应用。室内及现场应用结果表明：研制的弱凝胶护壁护心钻井液具有良好的流变性、降滤失性、抑制性（岩屑回收率96.3%）、护壁护心性能及环保性能（BOD5/COD比值24.6%,EC50值47950 mg/L）,能有效解决松散砂岩类地层孔壁坍塌、岩屑不易携带等问题,在松散地层钻探工程中具有广阔的应用前景。     

低密度水包油钻井液在中原油田水平井的应用

根据低压力储层水平井钻井油气层保护要求,通过室内研究形成了密度在0.89~0.99 g/cm3之间可调,具有良好乳化稳定性和流变性,防塌能力强的低密度水包油钻井液配方。在达平1井等井的现场应用中,水包油钻井液性能稳定,易于维护调节,钻井施工安全快速,能够满足低压水平井近平衡、欠平衡钻井和地质要求,保护储层作用明显,收到了良好的应用效果。     

Bioremediation of heavily hydrocarbon-contaminated drilling wastes by composting

Oil-based drilling cuttings comprise a large and hazardous waste stream generated by oil and gas wells drilling operations. Oil-based cuttings are muddy materials with high contents of salts and hydrocarbons. Composting strategies have shown to be effective in the biodegradation of petroleum hydrocarbons, and it offers numerous advantages in comparison with other bioremediation methods. In order to assess the effectiveness of drilling cuttings bioremediation by composting with food and garden wastes, an experiment was conducted in 60-L reactors for 151 days. Four treatments were carried out: only oil-based cuttings, two proportions (in a volume basis) of organic wastes to drilling cuttings (33 and 75 %) and only organic wastes (as a traditional composting reference), with pine-tree woodchips as bulking agent. High degradation percentages of total hydrocarbons (≈82 %), n-alkanes (≈96 %) and the 16 USEPA-listed polycyclic aromatic hydrocarbons (≈93 %) were reached in the treatment with 75 % of organic wastes, and applying 33 % of organic wastes was not more effective than not applying organic wastes for the drilling cuttings hydrocarbons biodegradation. Furthermore, in the treatment with 75 % of organic wastes, alkanes half-life and polycyclic aromatic hydrocarbons half-life were about 10 times and four times lower, respectively, than those in the treatment with 33 % of organic wastes. Possibly, lower hydrocarbons and salts initial concentrations (i.e., lower toxicity), higher microbial counts, adequate nutrient proportions and water content supported a high biological activity with a consequent elevated biodegradation rate in the treatment with 75 % of organic wastes.     

环境科学钻探取样技术研究

为了给环境科学研究提供地下的真实原状样品,研究了具有国际先进水平的射流式取样技术、液压快速压入取样技术以及环保型钻井液。在新疆罗布泊、吐鲁番和北京周口店等地进行钻探实验,实验结果表明：射流式取心技术在采心过程中能有效地减少钻具的振动,防止岩心自磨,提高卡取岩心的可靠性,从而显著地提高岩心的采取率;液压快速压入取样技术适用于松散地层,能快速压入地层,土心采取率高,并且土心样品的原始结构完整、代表性强;环保型钻井液具有优良的综合性能,低滤失性、强抑制性和优良的润滑性,能有效保护孔壁的稳定性和松散岩心的完整性,起到既护壁又护心的作用,同时对环境无污染。     

托普台区块高渗透地层随钻堵漏剂配方优化

托普台区块上部地层以砂泥岩层、砾质砂岩为主,容易发生漏点不明确、漏失段长的高渗透性漏失。通过对堵漏材料的配伍性评价及合理级配,优选出了一种适合高渗透性漏失地层的随钻堵漏剂。该堵漏剂对钻井液流变性影响小,可降低钻井液API滤失量,对沙床封堵后承压能力＞10 MPa,在TP328X井的应用表明,高强度弹性石墨颗粒复合凝胶堵漏对于高压差、高渗透漏失的工况,可以有效封堵漏层,特别适用于对于漏层不明、漏涌同层、裸眼等复杂井况。     

水敏性地层钻探用接枝淀粉聚合物泥浆体系研究

以接枝淀粉共聚物为降失水荆,选择抑制荆、防塌剂、润滑剂、包被剂、膨润土等处理剂,优化设计了水敏性地层用接枝淀粉聚合物泥浆体系。经过测试,该体系的API失水为7ml,相对膨胀降低率84．2％,岩屑回收率92％,摩阻系数0．07。该体系在水敏性地层的钻探施工中取得了良好的使用效果。