MAKE-UP MATERIALS AND ADDITIVES Principles of Drilling Fluids 钻井液工艺原理 Chapter 6 MAKE-UP MATERIALS AND ADDITIVES 造浆材料与处理剂 Prof. Dr. Xiuhua Zheng E-mail: Xiuhuazh@cugb.edu.cn Exploration Dept. School of Engineering and Technology, China University of Geosciences(Beijing) 中国地质大学(北京)工程技术学院勘查教研室

Answers Test for §5 Pore or fracture in formation 压差 地层孔隙（裂隙） 渗透率 滤液 初失水 压差卡钻 泥饼中的水分 粒径及粒径分布 孔隙度 静失水和动失水 Pore or fracture in formation permeability filtrate mud spurt differential sticking water retained in the cake Particle size and particle distribution porosity static and dynamic filtration

Glossary for §6 无机处理剂 Inorganic agents 加重剂 Weighting Materials 碳酸钠 粘土改性 沉淀作用 络合作用 氢氧化钙 氯化钠 聚磷酸钠 螯合作用 Inorganic agents Weighting Materials Sodium carbonate clay beneficiation precipitation complexing Calcium hydroxide Potassium chloride sodium polyphosphates sequestration

Glossary for §6 单体 Monomer 非离子 non-ionic 阴离子或负电性 阳离子或正电性 碳化合物 有机胶质材料 降失水 稳定粘土 乳化剂 润滑剂 Monomer non-ionic anionic or negatively charged cationic or positively charged compounds of carbon Organic colloidal materials reduce filtration stabilize clays emulsifiers lubricants

Contents Water(水) Bentonite(膨润土) Materials to Increase Density(加重材料) Inorganic Chemical Additives(无机处理剂) Polymers(聚合物)

1. Water Water affects the drilling fluid properties in various aspects, such as the yield of Bentonite, the pH value.

第二类分类方法是按其在钻井液中所起的作用或功能分类。我国钻井液标准化委员会根据国际上的分类法，并结合我国的具体情况，将钻井液配浆材料和处理剂共分为以下16类，即(1)降滤失剂(Filtration Reducer)；(2)增粘剂(Viscosifier)；(3)乳化剂(Emulsifier)使油水乳化产生乳状液；(4)页岩抑制剂(Shale lnhibitor)；(5)堵漏剂(Lost Circulation Material)；(6)降粘剂(Thinner)；(7)缓蚀剂(Corrosion lnhibitor)；(8)粘土类(Clay)；(9)润滑剂(Lubricant)；(10)加重剂(Weighting Agent)；(11)杀菌剂(Bactericide)；(12) 消泡剂(Defoamer)；(13)泡沫剂(Foaming Agent)；(14)絮凝剂(Flocculant)；（15)解卡剂(Pipe-Freeing Agent)；(16)其它类(Others)等。

配浆水 水是配制各种钻井液时不可缺少的基本组分。在水基钻井液中，水是分散介质，大多数处理剂均通过溶解于水而发挥其作用；在油包水乳化钻井液中，水(通常是含CaCl2或NaCl的盐水)是分散相。甚至在泡沫钻井流体中，水也是不可缺少的连续相。 在钻井液工艺中，根据水中可溶性无机盐含量的多少，一般将配浆水分为以下三类：含盐量较少(总盐度低于1%)的淡水，含盐量较多的盐水和含盐量达饱和的饱和盐水，与之相应的钻井液分别称做淡水钻井液、盐水钻井液和饱和盐水钻井液。 此外，常将含Ca 2+、Mg2+较多的水称为硬水，钻探用水多为软水，钙离子1.5-3.0 meq/L。

2.Bentonite(膨润土) 膨润土是水基钻井液的重要配浆材料：为具有蒙脱石的物理化学性质，含蒙脱石不少于85％的粘土矿物。一般要求1t膨润土至少能够配制出粘度为15mPa·s的钻井液16m3。 钠膨润土的造浆率一般较高，而钙膨润土则需要通过加入纯碱（Na2CO3）使之转化为钠膨润土后方可使用。 目前我国将配制钻井液所用的膨润土分为三个等级：一级为符合API标准的钠膨润土；二级为改性土，经过改性符合OCMA标准要求；三级为较次的配浆土，仅用于性能要求不高的钻井液。

2.1 Mining and Processing (开采与加工) Bentonite deposits are normally exploited by quarrying(采石). Extracted bentonite is distinctly solid, even with a high moisture content of approximately 30%. The material is initially crushed and, if necessary, activated with the addition of soda ash (Na2CO3). Bentonite is subsequently dried (air and/or forced drying) to reach the moisture content of approximately 15%. According to the final application, bentonite is either sieved (granular form) or milled (into powder and superfine powder form). For special applications, bentonite is purified by removing the associated gangue minerals, or treated with acids to produce acid activated bentonite (bleaching earths), or treated with organics to produce organoclays.

http://www.ima-eu.org/en/eubaindex.htm

Bentonite Qualities: Calcium-Bentonite (non-activated Bentonite): Bentonite that is predominantly occupied by Ca 2+ or Mg 2+-ions in the intermediate layers. Activated Bentonite: Bentonite whose initial composition of Ca 2+ -ions in the intermediate layer has been replaced with Na+-ions in a technical process (alkali-activation). Natural Sodium-Bentonite (usually Wyoming-Bentonite, but also found in other locations): Bentonite predominantly occupied by Na 2+-ions in the intermediate layers. Ca 2+ or Mg 2+ -ions can also occur commonly in Na-bentonite in varying concentrations. Organophilic Bentonite (organoclays): Bentonite whose cations in the intermediate layers have been replaced by polar organic molecules (e.g. alkylammoniumions). They are hydrophobic and can swell in organic solvents. Acid Activated Bentonite: Bentonite whose structure has been partially dissolved by treatment with acids. Depending on degree of activation, original Ca 2+, Mg 2+, and Na + cations are mostly removed, and part of Al, Fe, Mg, Si from the lattice are dissolved. Acid activated bentonite exhibits high surface area > 200 m 2/g and large micropore volume.

API Bentonite Table 6-1 Bentonite Requirement for API Specification Moisture at point of manufacture 10%(maximum) Wet screen analysis(200 mesh screen residue) 4%(maximum) Properties of a suspension of bentonite(as received) in 350 ml distilled water; aged overnight; restirred 5 min. Viscometer dial reading 600 rpm 30 (minimum) Yield point 3 Plastic Viscosity (maximum) Filtrate loss -(100 psi 24 .) 15 ml (maximum) 1lb/ft2=47.8803Pa

Approximate Amounts for some Applications Added to Fresh Water Added to Fresh Water Mud (lb/bbl) (kg/m3) Normal drilling conditions Stabilize caving formations Loss of circulation 13-22 25-35 30-40 35-60 70-100 85-110 4-10 9-18 10-20 11-28 25-50 28-56 Loss of circulation plug Added to Diesel Oil 400 1000

膨润土逐渐分散在淡水中致使泥浆的粘度、切力不断增加的过程称为造浆，在添加主要处理剂之前的预水化膨润土浆常称做原浆或基浆。几乎在所有室内实验中，首先都要进行原浆的配制。由于蒙脱石含量和阳离子交换容量各不相同，来自不同产地的膨润土，其造浆效果往往有很大差别。几种典型粘土造浆的曲线如图6-1所示。

造浆率(Yield of Clay) 常将每吨粘土能配出表观粘度为15mPa·s的钻井液体积称做粘土的造浆率(Yield of Clay)。通常配浆土的质量是以造浆率来衡量的。从图6-1还可看出，配制1m315mPa·s的钻井液只需57kg怀俄明优质膨润土，如使用低造浆率粘土，则需570kg，两者的用量为1:10。经换算，用1 t优质膨润土可配制出表观粘度为15mPa·s的泥浆约16m3，而1t低造浆率粘土只能造浆约1.6 m3，相差亦近10倍。使用优质膨润土配浆，泥浆密度仅为1.03～1.04g／cm3时，表观粘度即可达到10～15 mPa·s；而使用低造浆率粘土配浆，泥浆密度必须增至1.35~1.40g／cm3时，其表观粘度才能达到同样的数值。因此，尽可能选用优质膨润土配浆，对减少体系中的固相含量，提高钻速有着重要的意义。

22.5g 土+350ml水， 符合API标准，求造浆率？

纯碱（Na2CO3）？ 配制原浆时，还需加入适量纯碱，以提高粘土的造浆率。纯碱的加入量依粘土中钙离子的含量而异，可通过小型试验确定。一般约为配浆土质量的5％。加入纯碱的目的是除去粘土中的部分钙离子，将钙质土转变为钠质土，从而使粘土颗粒的水化作用进一步增强，分散度进一步提高。因此，在原浆中加入纯适量碱后，一般会使表观粘度增大，滤失量减小。如果随着纯碱加入滤失量反而增大，则表明纯碱加过量了(?)。

配制一定密度泥浆所需的膨润土及水量可由下式求得: mc--所需膨润土的质量，t ； --膨润土密度，g／cm3； Vm--所配制原浆的体积，m3； --原浆密度，g／c m3； Vw--所需水量，m3。

2.3 Beneficiated and Super-Yield Bentonite （粘土改性提高造浆率） Terms such as peptized（胶溶）, beneficiated and extra-high yield describe bentonites to which organic polymers(有机聚合物) (and sometimes also soda ash) have been added during processing. These products made with Western bentonite in America are useful as starting or spud muds（开孔泥浆）, in low-solids muds（低固相泥浆）, and in applications where cost of transportation is extremely high. Less than half as much of such a material is needed compared to the amount of API-specification bentonite.

3. Materials to Increase Density (加重材料) 加重材料(Weighting Material)又称加重剂，由不溶于水的惰性物质经研磨加工制备而成。为了对付高压地层和稳定井壁，需将其添加到钻井液中以提高钻井液的密度。加重材料应具备的条件是自身的密度大，磨损性小，易粉碎；并且应属于惰性物质，既不溶于钻井液，也不与钻井液中的其它组分发生相互作用。 钻井液的常用加重材料有以下几种：(1)重晶石粉(Barite-4.2 )；(2)石灰石粉(Limestone-2.7~2.9) ；(3)铁矿粉 (Hematite-4.9~5.3)和钛铁矿粉(Ilmenite-4.5~5.1) (4)方铅矿粉(Galena-7.4~7.7) 。 2.30 1.68 3.0

Materials to Increase Density Pricipal Component Specific Gravity Hardness Moh’s Scale Galena Hematitc Magnetite Iron oxide(manufactured) Lllmenite Barite Siderite Celestitc Dolomite Calcite PbS Fe2O3 Fe3O4 FeO.TiO2 BaSO4 FeCO3 SrSO4 CaCO3, MgCO3 CaCO3 7.4-7.7 .3 5.0-5.2 4-7 4.5-5.1 4.2-4.5 3.7-3.9 2.8-2.9 2.6-2.8 2.5-2.7 5.5-6.5 5-6 2.5-3.5 3.5-4 3-3.5 3

Fig. 6-1 Effect of specific gravity of weighting material on the solids concentration of weighted muds Figure 6-1 shows the effect of the specific gravity of the weighting material on the solids concentration of weighted muds（加重泥浆）. For example, the solid content of mud weighted to 19.0 lb/gal (2.28 g/cm3) with material having a specific gravity of 4.2 is 39.5% by volume, as compared with 30% by volume for a material of 5.2 specific gravity.

Barite Requirements for APl Specification Specific gravity: 4.20, minimum Wet screen analysis: Residue on U.S. Sieve (ASTM) no. 200: 3.0% maximum Residue on U.S. Sieve (ASTM) no. 325: 5.0% minimum Soluble alkaline earth metals as calcium: 250 ppm, maximum

Calculation of Weighting Materials（加重材料的计算） 基本公式：

No limitation to the final fluid volume 1）加重后体积没有限制，则：

With limitation to the final fluid volume 2）加重后体积有限制，加重前必须排掉，则：

Dilution with water before weighting 根据： 推出：

4. Inorganic Chemicals 无机处理剂

无机处理剂在钻井液中的作用机理 无机处理剂都是水溶性的无机碱类和盐类，其中多数可提供阳离子和阴离子，也有一些与水形成胶体或生成络合物。它们在钻井液中的作用机理可归纳为以下方面： 1．离子交换吸附 2．调控钻井液的pH值 3．沉淀作用 4．络合作用 5．与有机处理剂生成可溶性盐 6．抑制溶解的作用

Sodium carbonate, Na2CO3 碳酸钠 Sodium carbonate turns Ca-Bentonite to Na-Bentonite through cation exchange and precipitation(沉淀作用), clay beneficiation(粘土改性) i.e.: Sodium carbonate can be used when the muds are invaded by Ca2+ by precipitation,

Sodium hydroxide, NaOH 氢氧化钠 Used in water muds to raise pH; to solubilize lignite(褐煤), lignosulfonate（木质素磺酸盐） and tannin（单宁） substances; to counteract corrosion, and to neutralize hydrogen sulfide（硫化氢） Concentration 0.6~11 kg/m3

Calcium oxide, CaO and Calcium hydroxide, Ca(OH)2 Calcium hydroxide, Ca(OH)2, Produced by adding calcium oxide to water ； 0.16% solubility of CaO; Used in lime muds（石灰泥浆）, high-calcium-ion muds, and for the removal of soluble carbonates.

Calcium sulfate, CaSO4 CaSO4, anhydrite（无水石膏）; CaSO4.2H2O, gypsum（熟石膏）, white of colorless crystals or powder with 2.31-2.32 g/cm3 density. Slightly soluble in water with about 0.2% solubility. Source of calcium ions in gyp muds. Concentration 2 to 8 lb/ bbl (6 to 23 kg/m3).

Calcium chloride, CaCl2 Calcium chloride, CaCl2, CaCl2.6H2O; white deliquescent crystals (75% solubility), granules, lumps, flakes with 1.68g/cm3 density. Used in hole-stabilizing oil muds; in calcium-treated muds, in the preparation of dense salt solutions for completion and workover, and for lowering the freezing point of water muds. Concentration ranges from 10 to 200 lb/bbl (28 to 570 kg/m3).

Sodium chloride, NaCl Sodium chloride, NaCl, table salt, halite(岩盐), rock salt; white crystals with 2.20 g/cm3. Used as produced or as prepared brine in completion（完井液） and workover（修井液） operations; to saturate water before drilling rock salt; to lower freezing point of mud; to raise the density (as a suspended solid) and act as a bridging agent in saturated solutions, and in hole-stabilizing oil muds. Concentration 10 to 25 lb/bbl (30 to 360 kg/m3).

Potassium chloride, KCl Potassium chloride, KCl, sylvite(钾盐), potash（苛性钾）; colorless or white crystals with 1.98 g/cm3 density. Shale inhibitor（页岩抑制剂）. Primary source of potassium ions for potassium-polymer muds(钾盐聚合物泥浆). Concentration 2 to 60 lb/bbl (6 to 170 kg/m3).

Sodium dichromate Na2Cr2O7.2H2O Sodium dichromate, Na2Cr2O7.2H2O; red-orange crystals with 2.35 g/cm3 density. Used as constituent of chrome lignosulfonate（木素磺算铬） and chrome lignite compositions for increased thermal stability, and to inhibit corrosion in salty muds. Concentration 0.1 to 2lb/bbl (0.3 to 6 kg/m3).

The sodium polyphosphates（聚磷酸钠） The sodium polyphosphates（聚磷酸钠） are very effective deflocculants（抗絮凝剂） for clays in fresh water and Fig.6-3 Schematic representation of a polyphosphate molecule adsorbed on clay crystal edge by bonding with exposed aluminum atoms were among the first thinners for mud. The glassy polyphosphates effectively soften hard water by forming soluble complexes（可溶性络合物） with calcium and magnesium ions. This action, called sequestration（螯合作用）, is applied in dispersing bentonite for filtration reduction（降失水）.

Sodium acid pyrophosphate（焦磷酸钠）, SAPP, Na2H2P2O7 Sodium tetraphosphate（四磷酸钠）, Na6P4O13 Sodium hexametaphosphate（六偏硫酸钠）, (NaPO3)6

Fig.6-2 Schematic representation of a polyphosphate molecule adsorbed on clay crystal edge by bonding with exposed aluminum atoms

硅酸钠 硅酸钠(Sodium Silicate)俗名水玻璃或泡花碱。分子式为Na2O·nSiO4，式中n称为水玻璃的模数，即二氧化硅与氧化钠的分子个数之比。n值越大，碱性越弱。n值在3以上的称为中性水玻璃，n值在3以下的称为碱性水玻璃。 硅酸盐钻井液是防塌钻井液的类型之一 。 水玻璃是一种堵漏剂。

混合金属层状氢氧化物 混合金属层状氢氧化物(Mixed Metal Layered Hydroxide Compounds，简称为MMH)由一种带正电的晶体胶粒所组成，常称为正电胶。目前，其产品有溶胶、浓胶和胶粉等三种剂型。实验表明，该处理剂对粘土水化有很强的抑制作用，与膨润土和水所形成的复合体具有独特的流变性能。

5. Polymers(聚合物)

Organic polymer（有机聚合物） composed of a number of repeating or similar units, or groups of atoms (called monomers单体) consisting primarily of compounds of carbon（碳化合物）. Organic colloidal materials（有机胶质材料） are used in drilling fluids to reduce filtration（降失水）, stabilize clays（稳定粘土）, flocculate drilled solids（絮凝固相）, increase carrying capacity（提高携岩能力）, and (incidentally) to serve as emulsifiers（乳化剂） and lubricants（润滑剂）.

Classification Some, such as the starches（淀粉） and guar gum（胍胶）, occur naturally, and are ready for use after slight processing. Others, such as xanthan gum（黄原胶）, employ natural processes in their production. Still other polymers, such as derivatives of the starches and gums, and sodium carboxymethylcellulose, might be called semi-synthetic(半合成). Antoher class of petrochemical derivatives（石化产品）, such as the polyacrylates and ethylene oxide polymers is purely synthetic.

Glossary about polymer The repeating units (monomers) that make up the polymer may be the same, or two or more monomers may be combined forming copolymers（共聚物）. Structurally, the polymer may be linear(线性) or branched（支链）. and these structures, either linear, branched, or both, may be cross-linked（交联）, i.e., tied together by covalent bonds（共价键）. Further variations(变异) in the structure of polymers exist because of the possibility of combining two monomers in several different ways. The structure may coil（卷曲） or uncoil, depending upon its environment.

Critical examination of the factors for selection of polymers （选用聚合物的影响因素） Among the factors affecting performance are the effects of shear conditions, temperature, dissolved salts and alkaline materials, microorganisms, and time of use on the polymer. If the application takes place in completion operations, both the solubility of the polymer in acids and the possible plugging action（堵塞） of the polymer on the productive formation must be considered. Other factors involved are ease of handling and mixing, possible environmental effects, and cost of the polymer.

5.1 Fundamental Structure of Polymers (聚合物基本结构) Type of monomer（单体类型） or monomers. Number of monomers joined together to form a chain --i.e. molecular weight（分子量）. Number of cross linking（交联） or branching groups（支链） in the chain. Type and extent of subsequent chemical modification（后期化学改性）. Fig.6-3.Fundamental polymer structure

Molecular weight or chain length 分子量或链长 Fig.6-4. Different molecular weight distribution curves

Type of reactive groups 反应基团类型 The groups that can be attached onto the polymer can be divided into three groups: non-ionic(非离子) anionic or negatively charged(阴离子或负离子) cationic or positively charged(阳离子或正离子)

Types of groups Class Group Name Formula Non-ionic hydroxyl —OH ether linkage R—O—R ester —O—CH3 Anionic phenolic OH C6H5OH→C6H5O- carboxyl COOH→COO- —sulphonic —SO3 H→—SO3- —phosphate —PO3H→—PO3- Cationic —amine —NH3→—NH4+

Three dimensional structure The eventual shape or three dimensional structure of the molecule will depend on the following factors: Branching or cross-linking in the structure Concentration and type of groups on the molecules pH Ionic strength(离子浓度), or salt concentration(盐浓度) Fig. 6-5. Effect of electrolyte concentration on polymer configuration

Relationship between Polymer Structure and Function in Drilling Fluids 聚合物结构与功能的关系 Main characteristics Viscosity High molecular weight Viscosity and gellation properties High molecular weight and highly branched structure or cross linking agent Viscosity in salt solutions High molecular weight and non-ionic or highly substituted anionic types Deflocculation, dispersion or thinning action Low molecular weight negatively charged at alkaline pH values Flocculation High molecular weight with charged groups to adsorb onto clays Surfactant Hydrophobic group and hydrophylic group on same molecule Fluid loss additive Form colloidal particles

The viscosity is due to interactions between the polymer molecules and water, between the polymers themselves and between the polymers and solids when these are present. Solutions that exhibit this behaviour are called pseudoplastic or shear thinning fluids(假塑性或剪切稀释流体). These forces giving rise to the viscosity can be disrupted by supplying energy or shear. The result of this is that the greater the shear rate, the lower the viscosity becomes. This is ideal flow behaviour for drilling fluids, because low viscosity is required at the high shear rate zone near the bit and higher viscosities are needed in the lower shear rates in the annulus, to transport cuttings to the surface.

高低分子量聚合物浓度对水溶液粘度的影响 Fig.6-6. Effect of concentration on viscosity of a high and low molecular weight water soluble polymer

Types and functions of Polymers in drilling fluids 钻井液 Polymer Type Description Examples Functions Carboxymethyl cellulose ether CMC Polysaccharide linear polymer anionic-COO- groups High molecular wt Low molecular wt High viscosity CMC Low viscosity CMC Viscosifier, fluid loss additive Fluid loss additive Hydroxyethyl HEC Polysaccharide linear polymer non-ionic ether group high molecular weight Viscosifier-particularly for brines. Starch Polysaccharide highly branched forms colloidal solution normally non-ionic or anionic-COO- Corn. potatoes, tapioca, etc. Variously chemically modified Fluid loss control in salt solutions Bacterial gums polysaccharide Polysaccharide branched complex structure some anionic groups. High molecular weight Xanthan gums Viscosifier-particularly in salt water and where suspension properties are required

continued Natural gums from trees and shrubs Polysaccharide branched – high molecular weight some anionic groups complex structure Guar, Gum arabic Viscosifier Lignosulphonate Water soluble sulphonate derivative of lignin - range of metal salts Calcium lignosulphonate Calcium-chrome lignosulphonate Ferro-chrome lignosulphonate Thinner deflocculant fluid loss control Mined lignins Tannin Polyphosphates Metal salts of petrified humic acid Extracts from bark and wood Molecularly dehydrated phosphates Chrome lignite, Potassium lignite, Causticized lignite Quebracho Sodium acid pyrophosphate Water loss control and thinner Vinyl polymer Polymer of acrylic acid CH2=CHCOOH -CH2 -CH-CH2-CH- C=O C=O O-Na O-Na Low molecular weight <1,000 thinner. High molecular weight flocculant

continued Vinly polymer Co-polymer of acrylic acid and acrylamide in various ratios -CH2 -CH-CH2-CH C=O C=O O-Na+ NH2 Flocculant shale stablizer Co-polymer Vinyl acetate-maleic anhydride, high molecular weight -CH2 -CH-CH-CH- CO CO CO O=CCH3 OH OH Flocculant bentonite extender Surfactants Resin soaps calcium soap of tall oil lecithin Nonylphenolethoxylate alkyl sulphonates Synthetic polymers Emulsifier for water in oil emulsifier for oil in water drilling detergent n-Tridecyl polyoxy ethylene ethanol, nonyl phenol polyethylene glycol ether Foaming agent Surfactant Higher alcohols, sulphated vegetable oils Defoamer Fatty acid glycerides, ethoxylated long chain alkyldiamine Lubricant corrosion inhibtor

5.1 Thinners（稀释剂） Thinners are added to mud to reduce flow resistance（流动阻力）and gel development（形成凝胶）. Thinners typically have a relatively large anionic（大阴离子） component which adsorbed on positive sites of the clay particles, thereby reducing the attractive forces between the particles without affecting the hydration of the clay.

Deflocculants解絮凝剂 Deflocculants, or thinners, in alkaline clay based systems, by adsorption of the negatively charged polymer onto the clay platelets, thus neutralising positive charges and creating an overall negative charge.

Fig. 6-7. Diagram to illustrate low M. W Fig.6-7. Diagram to illustrate low M.W. polymers acting as deflocculant and high M.W. polymers acting as flocculants

Materials commonly used as thinners Materials commonly used as thinners for clay-water muds can be broadly classified as: (1) plant tannins（单宁类植物）, (2) polyphosphates（多磷酸盐）, (3) lignitic materials（褐煤）, and (4) lignosulfonates（木素磺酸盐）.

5.1.1 Tannins (NaT) 单宁类 Composition and Source. The word tannins is a collective term for a group of complex astringent substances, made up of carbon, hydrogen and oxygen, and, in some cases, containing small amounts of nitrogen and phosphorous. They are very weak acids（弱酸）. Their molecular weight is in the range of 300 to 1,000. They are readily soluble in alkalies（碱） and are precipitated by heavy metals（重金属）.

Tannins Tannins are broadly classified chemically as hydrolyzable tannins（可水解单宁酸）, consisting of esters（酯） of one or more polyphenolic acids（多酚酸）, such as gallic acid(五倍子酸,没食子酸), or condensed tannins（浓缩单宁酸）. The hydrolyzable tannins are also called gallotannins（没食子丹宁, or pyrogallol tannins（焦棓酸）, and the condensed tannins are called flavotannins, or catechol（邻苯二酚） tannins.

Gallic acid is then neutralized(中和) by NaOH to produce Fig.6-1 Gallic acid hydrolyzed from double gallic acid Fig.6-2 Deflocculation Mechanism of Sodium Tannate Gallic acid is then neutralized(中和) by NaOH to produce Sodium Tannate, and to deflocculate(解絮凝) by breaking up（拆散 ）the Gel-Structure of the Muds.

Modified Tannins. Quebracho can be made cold-water soluble by treatment with sodium bisulfite(亚硫酸钠). Further modifications can be made to produce metal complexes(金属络合物) of sulfoalkylated tannins（磺化单宁） that are easily dissolved in water, and are more effective in thinning and in reducing filtration than is the original tannin. A typical method of preparing sulfomethylated tannin（磺甲基单宁－SMT） involves adding formaldehyde（甲醛） and sodium bisulfite（亚硫酸钠） to a solution of quebracho and caustic soda, and heating the mixture.

5.1.2 Lignosulfonates（木素磺酸盐） Source and Composition: Lignosulfonates are byproducts of the sulfite(亞硫酸盐) process for the separation of cellulose pulp（纤维素纸浆） from wood. The polysaccharides（聚糖） (called holocellulose综纤维素) make up 70 to 80% of the tissue, and lignin(木质素) is the remainder

Lignins and Lignosulphonates(木质素和木素磺酸盐) Lignin is a major component of wood and binds the bundles of cellulose fibres together. To produce cellulose pulp for paper production, the lignin may be solubilised by reaction in hot alkali and bisulphite. The structure of lignin is not known with any precision.

Lignosulfonate

Ferrochrome lignosulfonate(铁铬木素磺酸盐-FCLS) 1.磺化基团+螯合：水溶性；抗盐、钙。 2.C-S连接＋螯合: 抗高温达150℃。 Cr3＋的螯合

Properties of Ferrochrome Lignosulfonate Ferrochrome lignosulfonate can be used in drilling fluids when temperature reaching 150℃. The lignosulfonates serve both as thinner and emulsifier in saturated salt water mud. 螯合：木质素磺酸分子与金属离子络合时，一个分子同时有 两个官能团与同一个离子络合成为螯合。 磺化度：磺酸基团的S与木素磺酸的质量比。 低于2~3%，难溶甚至不溶； 亚硫酸盐蒸煮，其磺化度>5％。

Thinning mechanism Adsorption of the negative lignosulfonate micelles on the edge surfaces of the clay particles. Adsorption of lignosulfonate on clay surfaces reduces clay swelling and cleavage, thus promoting hole stabilization and recovery of undispersed cuttings.

Polyphosphates（多磷酸盐） The monomers, the orthophosphates, are polymerized by removal of water to form the metaphosphates and pyrophosphates. The meta and pyrophosphates are reacted with each other to form the polyphosphates.

5.2 Filtration Reducer（Filtration Control Agent）降滤失剂 Filtrate invaded into the formation causes downhole problems, such as shale swelling, collapsing during drilling, and damaging the production zone. Filtration control agent is then introduced, with which flexible, thin and compact mud cake with low-permeability can be formed on the wall of borehole to reduce the filtrate volume into the rock. Cellulose（纤维素）, humic acid(腐殖酸), acrylic acid(丙烯酸), starch（淀粉） and resin（树脂） are used as filtration reducer.

5.2.1 Sodium Carboxymethylcellulose（羧甲基纤维素钠）

羟基－吸附基团 Adsorption group 醚氧剂－吸附基团 羧钠基－水化基团 Hydration group 纤维素的聚合度DP：组成每个钠羧甲基纤维素分子的环式葡萄糖的链节数。 纤维素的取代度DS：纤维素分子每一葡萄糖单元上的3个羟基中，氢被取代 而生成的醚的个数。

HV, MV, LV-CMC Filtration is sharply reduced by low concentrations of CMC, and especially by the higher molecular weight (and higher viscosity) products (HV-CMC, 1%, 400-500mPa.s,DS：0.6-0.65, DP>700 ) The low-viscosity grade CMC is used for filtration reduction of heavily weighted muds (LV-CMC, 2%, <50mPa.s,DS：0.8-0.9, DP:500) The medium-viscosity grade is used in muds having the common range of solids contents (MV-CMC, 2%, 50-270mPa.s,DS：0.8-0.85, DP>600 )

Mechanism of filtration reduction－1 CMC在钻井液中电离生成长链的多价阴离子。其分子链上的羟基和醚氧基 为吸附基团，而羧钠基为水化基团。羟基和醚氧基通过与粘土颗粒表面上的氧形成氢键或与粘土颗粒断键边缘上的Al3+之间形成配位键使CMC能吸附在粘土上；而多个羧钠基通过水化使粘土颗粒表面水化膜变厚，粘土颗粒表面ξ电位的绝对值升高，负电量增加，从而阻止粘土颗粒之间因碰撞而聚结成大颗粒(护胶作用)。

Mechanism of filtration reduction－2 ,3 多个粘土细颗粒会同时吸附在CMC的一条分子链上，形成布满整个体系的混合网状结构，从而提高了粘土颗粒的聚结稳定性，有利于保持钻井液中细颗粒的含量，形成致密的滤饼，降低滤失量。 具有高粘度和弹性的吸附水化层对泥饼的堵孔作用和CMC溶液的高粘度也在一定程度上起降滤失的作用。

Hydroxyethyl Cellulose (HEC) The production process for making HEC is based on the reaction between alkali cellulose and ethylene oxide as follows.

5.2.2 Humic acids（腐殖酸） Humic acids（腐殖酸）, are closely related phenolic, carboxylic compounds（羟基苯羧酸）, probably associated by hydrogen bonding. Molecular weights range from 300 to 4,000. Because of the complexity of the source materials, it is not surprising that the details of the structure of humic acid have not been agreed upon. One of the possible models is based on a hydroxyquinone structure（羟基醌）.

腐殖酸的大致结构 主要的官能团有羧基、 酚羟基、醇羟基、醌基、 甲氧基和羰基等。 由于其中有较多可与 粘土吸附的官能团， 特别是邻位双酚羟基， 同时又含有水化作用 较强的羧钠基等 水化基团， 使腐植酸钠不但具有： 很好的降滤失作用， 还兼有降粘作用。

磺甲基褐煤 褐煤与甲醛、Na2SO4 (或NaHSO3)在pH为9～11的条件下进行磺甲基化反应，可制得磺甲基褐煤，其代号为SMC。所得产品进一步用Na2Cr2O7，进行氧化和整合，生成的磺甲基腐植酸铬处理效果会更好。 由于引入了磺甲基水化基团，与煤碱剂相比，磺甲基褐煤的降滤失效果更进一步增强。磺甲基褐煤是我国用于深井的“三磺”处理剂之一。在200～230℃的高温下能有效地控制淡水钻井液的滤失量和粘度。其缺点是抗盐效果较差，在200℃单独使用时，抗盐不超过3％。但与磺甲基酚醛树脂配合处理时，抗盐能力可大大提高。

5.2.3 Acrylic Polymer Applications（丙烯酸聚合物的应用） 由于Na·HPAN分子的主链为C—C键，还带有热稳定性很强的腈基，因此可抗200℃以上高温。该处理剂的抗盐能力也较强，但抗钙能力较弱。当Ca 2＋浓度过大时，会产生絮状沉淀。

PAC系列产品 PAC系列产品是指各种复合离子型的聚丙烯酸盐(PAC)聚合物，实际上是具有不同取代基的乙烯基单体及其盐类的共聚物，通过在高分子链节上引入不同含量的羧基、羧钠基、羧胺基、酰胺基、腈基、磺酸基和羟基等共聚而成。该系列产品主要用于聚合物钻井液体系。由于各种官能团的协同作用，该类聚合物在各种复杂地层和不同的矿化度、温度条件下均能发挥其作用。只要调整好聚合物分子链节中各官能团的种类、数量、比例、聚合度及分子构型，就可设计和研制出一系列的处理剂，以满足降滤失、增粘和降粘等要求。其中应用较广的是PAC141、PAC142和PAC143等三种产品。

PAC141 PAC141是丙烯酸、丙烯酰胺、丙烯酸钠和丙烯酸钙的四元共聚物。 它在降滤失的同时，还兼有增粘作用，并且还能调节流型，改进钻井液的剪切稀释性能。 该处理剂能抗180℃的高温，抗盐可达饱和。

PAC142 PAC142是丙烯酸、丙烯酰胺、丙烯腈和丙烯磺酸钠的共聚物。 淡水钻井液中，其推荐加量为0．2％～0．4％； 在饱和盐水钻井液中，推荐加量为1．0％～0.5％。

PAC143 PAC143是由多种乙烯基单体及其盐类共聚而成的水溶性高聚物，其相对分子质量为150万～200万，分子链中含有羧基、羧钠基、羧钙基、酰胺基、腈基和磺酸基等多种官能团。 该产品为各种矿化度的水基钻井液的降滤失剂，并且能抑制泥页岩水化分散。 在淡水钻井液中的推荐加量为0．2％~0．5％； 在海水和饱和盐水钻井液中，推荐加量为0．5％～2％。

5.2.4 磺甲基酚醛树脂 磺甲基酚醛树脂(SMP-1，SMP-2)是一种抗高温降滤失剂。 其合成路线是：先在酸性条件(pH＝3～4)下使甲醛与苯酚反应，生成线型酚醛树脂；再在碱性条件下加入磺甲基化试剂进行分步磺化；通过适当控制反应条件，可得到磺化度较高和相对分子质量较大的产品。 它的另一种合成路线是：将苯酚、甲醛、亚硫酸钠和亚硫酸氢钠一次投料，在碱催化条件下，缩合和磺化反应同时进行，最后生成磺甲基酚醛树脂。

磺甲基酚醛树脂分子的主链由亚甲基桥和苯环组成，又引入了大量磺酸基，故热稳定性强，可抗180～200℃的高温。因引入磺酸基的数量不同，抗无机电解质的能力会有所差别。目前使用量很大的SMP-1型产品可用于矿化度小于1×105mg／l的钻井液，而SMP-2型产品可抗盐至饱和，抗钙也可达2 000mg／l，是主要用于饱和盐水钻井液的降滤失剂。此外，磺甲基酚醛树脂还能改善滤饼的润滑性，对井壁也有一定的稳定作用。其加量通常在3％～5％之间。

5.2.5 Starch 在某些钻井液中，加入淀粉不仅可以降低滤失量，而且还有助于提高钻井液中粘土颗粒的聚结稳定性。淀粉在淡水、海水和饱和盐水钻井液中均可使用。

5.3 Viscosifier(增粘剂) Xanthan Gum: XC Polymer（生物聚合物） 增粘 降滤失

Natural Gums—Guar(胍胶) Guar gum is derived from the seed of the guar plant. It is a polysaccharide polymer with molecular weight of about 220.000. The repeating unit is composed of galactose(半乳糖) and manose. The probable structure is given in Fig.6-17.

5.4 页岩抑制剂 概括地讲，处理剂在钻井液中所起的作用主要有两个：一是维持钻井液性能稳定，二是保持井壁稳定。 凡是能有效地抑制页岩水化膨胀和分散，主要起稳定井壁作用的处理剂均可称做页岩抑制剂，又称防塌剂。

(1)氧化沥青 氧化沥青(Oxidized Asphalt)是将沥青加热并通入空气进行氧化后制得的产品。沥青经氧化后，沥青质含量增加，胶质含量降低。在物理性质上表现为软化点上升。使用不同的原料并通过控制氧化程度可制备出软化点不同的氧化沥青产品。 氧化沥青为黑色均匀分散的粉末，难溶于水，多数产品的软化点为150～160℃，细度为通过60目筛的部分占85％。主要在水基钻井液中用做页岩抑制剂，并兼有润滑作用，一般加量为1％～2％。此外，还可分散在油基钻井液中起增粘和降滤失作用。 氧化沥青的防塌作用主要是一种物理作用。它能够在一定的温度和压力下软化变形，从而封堵裂隙，并在井壁上形成一层致密的保护膜。在软化点以内，随温度升高，氧化沥青的降滤失能力和封堵裂隙能力增加，稳定井壁的效果增强。但超过软化点后，在正压差作用下，会使软化后的沥青流入岩石裂隙深处，因而不能再起封堵作用，稳定井壁的效果变差。因此，在选用该产品时，软化点是一个重要的指标。应使其软化点与所处理井段的井温相近，软化点过低或过高都会使处理效果大为降低。

(2)磺化沥青 目前使用的磺化沥青(Sulfonated Asphalt)实际上是磺化沥青的钠盐，代号为SAS。它是常规沥青用发烟H2SO4或SO3进行磺化后制得的产品。沥青经过磺化，引入了水化性能很强的磺酸基，使之从不溶于水变为可溶于水。磺化时应控制产品中含有的水溶性物质约占70％，既溶于水又溶于油的部分约占40％。磺化沥青为黑褐色膏状胶体或粉剂，软化点高于80℃，密度约为1g／cm3。 磺化沥青的防塌机理是：磺化沥青中由于含有磺酸基，水化作用很强，当吸附在页岩晶层断面上时，可阻止页岩颗粒的水化分散；同时不溶于水的部分又能起到填充孔喉和裂缝的封堵作用，并可覆盖在页岩表面，改善泥饼质量。但随着温度的升高，磺化沥青的封堵能力会有所下降。磺化沥青还在钻井液中起润滑和降低高温高压滤失量的作用，是一种多功能的有机处理剂。

(3)天然沥青和改性沥青 国内外使用天然沥青和各种化学改性沥青产品稳定井壁已有多年的历史。不同沥青类产品稳定井壁的机理不同。沥青粉的主要作用机理是，在钻遇页岩之前，往钻井液中加入该种物质，当钻遇页岩地层时，若沥青的软化点与地层温度相匹配，在井筒内正压差作用下，沥青产品会发生塑性流动，挤入页岩孔隙、裂缝和层面，封堵地层层理与裂隙，提高对裂缝的粘结力，在井壁处形成具有护壁作用的内、外泥饼。其中外泥饼与地层之间有一层致密的保护膜，使外泥饼难以被冲刷掉，从而可阻止水进入地层，起到稳定井壁的作用。 此外，为了提高其封堵与抑制能力，可将沥青类产品与其它有机物进行缩合。如磺化沥青与腐植酸钾的缩合物KAHM，俗称高改性沥青粉，在各类水基钻井液中均有很好的防塌效果。

5.5 Lost Circulation Materials （堵漏剂） Flaky Granular Fibrous Cellophane Cotton seed hulls Mica Vermiculite Calcium carbonate Coal Diatomaceous earth Gilsonite Nut shells Almond Pecan Walnut Olive pits Perlite Salt (only in saturated solutions) Synthetic resins Asbestos Bagasse Flax shives Hog hair Leather Mineral wool Paper Rubber tires Wood Bark Shavings Shreds(fibers)

各种堵漏剂的堵漏能力 堵漏剂名称 形状 尺 寸 质量浓度／kg·m-3 最大堵塞缝隙 坚果壳 颗粒状 5mm～lO号筛目占50％ 57 尺 寸 质量浓度／kg·m-3 最大堵塞缝隙 坚果壳 颗粒状 5mm～lO号筛目占50％ 57 5．20 塑料碎片 10～100号筛目占50％ 石灰石粉 114 3．18 硫矿粉 980 10～16号筛目占50％ 多孔隙珍珠石 5 mm～lO号筛目占50％ 172 2．69 赛璐珞粉 薄片状 19mm薄片 23 锯 末 纤维状 6mm大小 29 树 皮 13mm大小 干 草 12.5 mm大小 棉子皮 粉末 1．53 1．42 木 屑 6 mm大小 O．9l 1.6mm大小 O．43

抗高温处理剂的分子结构特征 为提高热稳定性，处理剂分子主链的连接键，以及主链与亲水基团的连接键应为“C—C”、“C—N”和“C—S”等键，应尽量避免分子中有易氧化的醚键和易水解的酯键。 为了使处理剂在高温下对粘土表面有较强的吸附能力，常在处理剂分子中引入Cr3+、Fe3+ 等高价金属阳离子，使之与有机处理剂形成络合物，如铬-腐植酸钠和铁铬盐等。 为了减轻高温去水化作用，处理剂分子中的主要水化基团应选用亲水性强的离子基，如磺酸基（—SO3–）、磺甲基（—CH2SO3–）和羧基（—COO–）等，以保证处理剂吸附在粘土颗粒表面后能形成较厚的水化膜，使钻井液具有较强的热稳定性。这就是在单宁、褐煤和酚醛树脂分子上引入磺甲基的原因。

常用的抗高温降粘剂 抗高温降粘剂与一般降粘剂的不同之处主要表现在：不仅能有效地拆散钻井液中粘土晶片以端-面和端-端连接而形成的网架结构，而且能通过高价阳离子的络合作用，有效地抑制粘土的高温分散。目前常用的抗高温降粘剂除铁铬木质素磺酸盐（FCLS）外，还有： A、磺甲基单宁（SMT） 简称磺化单宁，是磺甲基单宁酸钠与铬离子的络合物。外观为棕褐色粉末，吸水性强，其水溶液呈碱性。抗温可达180～200℃。其加量一般在1%以下，使用的pH范围为9～11。 B、磺甲基栲胶（SMK） 简称磺化栲胶。为棕褐色粉末或细颗粒，易溶于水，水溶液呈碱性。不含重金属离子，无毒，无污染，抗温可达180℃。其降粘性能与SMT相似，可任选一种使用。

抗高温降滤失剂 A、磺甲基褐煤（SMC） 简称磺化褐煤，是磺甲基腐植酸与铬酸盐交联后生成的络合物。为黑褐色粉末或颗粒，易溶于水。它既是抗高温降粘剂，同时又是抗高温降滤失剂。抗温可达200～220℃。一般用量为3～5%。 B、磺甲基酚醛树脂 简称磺化酚醛树脂，分为1型产品（SMP-1）和2型产品（SMP-2）。由于其分子结构主要由苯环、亚甲基和C—S键等组成，因此热稳定性很强；又由于含有强亲水基——磺甲基（—CH2SO3–），且磺化度高，故亲水性很强。在200～220℃甚至更高温度下，不会发生明显降解。 SMP-1与SMC复配使用的效果更好。这是由于与SMC复配后，SMP-1在粘土表面的吸附量可增加5～6倍，从而使其zeta电位明显增大，水化膜明显增厚，最终导致处理剂护胶能力增强，泥饼质量得以改善，泥饼渗透率和滤失量下降。

磺甲基酚醛树脂[（SMP-1）和（SMP-2）] 一些常用钻井液处理剂的抗温能力 处 理 剂 名 称 抗 温 能 力 单宁酸钠 130℃ 栲胶碱液 80～100℃ 铁铬盐(FCLS) 130～180℃ CMC 140～180℃ 腐植酸衍生物 180～200℃ 磺甲基单宁（SMT） 磺甲基褐煤（SMC） 200～220℃ 磺甲基酚醛树脂[（SMP-1）和（SMP-2）] 200℃ 水解聚丙烯腈（HPAN） 200～230℃ 淀粉及其衍生物 115～130℃

作业 How the properties of drilling fluid can be affected by water? What kind of Bentonite shall be used for making up muds with high quality? Using API Barite to increase 180 m3 of drilling fluid the density from 1.10g/cm3 to 1.25g/cm3, the final fluid volume is 180 m3 , then calculate: 1) How much muds shall be disposed before weighting; 2) How much barite shall be added?

Discussion Explain the functions and mechanisms of Sodium carbonate (Na2CO3), Sodium hydroxide (NaOH), Calcium chloride(CaCl2), Potassium chloride (KCl) and sodium polyphosphates. Expatiate the mechanism of NaT(Thinner) and CMC (Filtration reducer) by analyzing their structure separately. Write out the hydrolysis process of polyacrylonitrile(聚丙烯腈). Interpret the following concepts their functions: DS, DP, chelation(螯合作用), adsorption groups and hydration groups and.