高砂比压裂技术研究

应用由美国ＮＳＩ公司引进的“ｓｔｉｍｐｌａｎ”拟三维压裂设计软件，对影响裂缝内支撑剂铺置浓度的诸因素进行了灰色关联度分析，从中找出了主要的影响因素。并以高砂比压裂的技术指标为依据，研究了在目前压裂工艺水平下，进行高砂比压裂所必须遵循的原则。文中还对国内的高砂比压裂进行了实例分析，进一步论证了文中的观点。     

支撑剂异常影响裂缝导流能力的实验研究

阐述石英砂、树脂砂与人造陶粒的物理综合性能评价情况。对石英砂、树脂砂和人造陶粒三种支撑剂在不同闭合压力下的导流能力进行对比,并测试同种支撑剂不同粒度范围的导流能力。与以往实验室测试不同的是在三种支撑剂导流能力下降到一定数值后将闭合压力降低为零,再次测试三种支撑剂经高闭合压力后的导流能力情况,以此判断导流能力受到何种异常...     

控水压裂工艺方法及效果分析

针对不同储层的渗流特征以及压裂裂缝扩展规律,探讨油井控水压裂技术实施效果。分别通过选择性控水支撑剂、透油阻水压裂液、人工隔离层等工艺进行现场先导实验,观察分析控水工艺使用前后含水率与产油量的情况。根据不同高含水井区的工程地质特征,提出控水压裂工艺优化选择方案。     

裂缝性低渗透储层压裂技术研究

运用小型压降可以判断天然裂缝存在与否,以及天然裂缝的张开压力大小.裂缝性储层并不需要高导流能力的人工裂缝,沟通更多的储层区域和天然裂缝是保证油井压后高产稳产的关键.通过支撑剂优选、压裂液优化、施工工艺优化这三个方面的研究,来有效控制压裂液向天然裂缝的滤失,保证施工的成功率.     

循环应力加载条件下支撑剂破碎率实验研究

运用微机控制电液伺服万能试验机,对循环应力加载条件下支撑剂破碎率进行实验研究,考察不同支撑剂及不同应力加载次数下支撑剂的破碎率情况。实验结果表明：循环应力加载对支撑剂的破碎率影响很大。随着应力循环加载次数的增加,破碎率上升明显,且破碎率开始上升较快,随着循环次数的增加而上升缓慢。     

Sintering mechanism of high-intensity and low-density ceramic proppants prepared by recycling of waste ceramic sands

Waste ceramic sands were effectively used to prepare the high-intensity and low-density ceramic proppants, realising the recycling of the waste ceramic sands. The technology involved the pelletising in an intensive mixer, in which the waste ceramic sands and other starting materials were added, and followed by heat-treatment under different sintering conditions. The sintering temperature, holding time and heating rate were optimised by investigating the crystalline phase, microstructure, density and breakage ratio of the obtained proppants. The results showed that the proppants sintered at 1260°C for 2?h with a heating rate of 5°C?min^–1 under air atmosphere exhibited high crush resistance and low density, with the breakage ratio of 8.5% under 52?MPa closure pressure and bulk density of 1.65?g?cm^–3. The proppants prepared by bauxite, waste ceramic sands and sintering aids are promising candidates as high-intensity and low-density fracturing proppants in future applications.     

The Synthesis and Characterization of a Clean Hydrofracturing Fluid

Abstract

Surfactant-based fracturing gels are considered as clean gels due to the absence of insoluble residues after hydraulic fracturing of tight reservoir. Conventionally used highly viscous polymer gels damage the formation by blocking the fluid path in a fractured formation. The present work has been accomplished with the purpose of evaluating an anionic surfactant-based gel for hydraulic fracturing. Rheological properties and proppant carrying capacity of the synthesized gel were studied as a function of shear rate, temperature, and pH, which affect the gel behavior at the downhole. Proppant carrying capacity was also reported with varying proppant loadings. Rheological properties and proppant carrying capacity of synthesized gel were compared with conventionally used guar gel.     

Study on rheology and thermal stability of mixed (nonionic–anionic) surfactant based fracturing fluids

Mixed surfactant systems have gained significant importance in the development of fracturing fluid due to polymorphism of self‐assembly structures that have combined properties of the surfactants in the mixture. In this article, a comparative study on the phase behavior and viscoelastic properties of mixed surfactant based fluids, prepared from Tween 80+NaOA/2‐ethyl hexanol/clove oil/water and Tween 20+NaOA/2‐ethyl hexanol/clove oil/water quaternary system is investigated in details. The viscoelastic surfactant (VES) based fluids prepared from the former system offered superior rheological properties than the latter system. The addition of 0.1% NaOH and 500 ppm ZnO nano‐particles in the VES fluids presented enhanced viscoelastic properties as concluded by static and dynamic rheological tests. Miscibility test indicated the miscibility of the VES fluids with water, unlike in the presence of diesel oil and satisfactory proppant suspension capabilities were exhibited by the developed fluids. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2177–2187, 2016     

添加锰矿粉和碳酸钙对铝硅质陶粒支撑剂材料性能的影响

以二级铝矾土生料、黏土为原料,以锰矿粉和碳酸钙为烧结剂,制备了高强度陶粒支撑剂材料,并讨论了锰矿粉加入量(w)0、1.0%、3.0%、5.0%、7.0%和碳酸钙加入量(w)0.5%、1.0%、1.5%、2.0%以及热处理温度为1 280、1 320、1 360、1 400℃时对支撑剂材料性能的影响。结果表明:随锰矿粉加入量的增加,试样烧结致密度提高,强度增大,当锰矿粉加入量≥5.0%(w)时,试样的强度基本不变;在加入5.0%(w)锰矿粉基础上,添加碳酸钙,试样烧后强度随碳酸钙加入量的提高而提高;碳酸钙加入量为2.0%(w)时,试样的强度达到275 MPa;同时添加5.0%(w)锰矿粉和2.0%(w)碳酸钙的试样的较佳热处理温度为1 360℃。     

多尺度支撑剂组合加砂技术在压裂过程中的应用研究

随着勘探开发井深度的增加及开采难度的加大,压裂裂缝的复杂程度也越来越大,窄裂缝、弯曲裂缝、多裂缝不断涌现,经常导致加砂困难或支撑裂缝质量差等问题。同时在压后返排过程中时常出现支撑剂返吐现象。以上问题严重影响了压裂效果。多尺度支撑剂组合加砂技术是把不同粒径支撑剂的优点结合起来,在裂缝复杂或狭窄的区域加入流动性较好的小粒径支撑剂,在裂缝条件较好的区域添加大粒径支撑剂,提高压裂成功率及支撑裂缝的质量,减少了支撑剂回吐的几率,避免在裂缝口部出现瓶颈现象。本文分别从理论上研究了小粒径加砂、大粒径加砂以及组合支撑剂加砂技术的特点,然后进行了室内试验研究以及产能分析,最终得出了不同粒径支撑剂组合加砂技术的优点及应用方法,为提高压裂成功率及裂缝的质量提供了依据。