548809079.doc第九章钻井液一.单词准备mud 泥浆drilling fluid 钻井液cutting 岩屑mud chemical 泥浆药品mud cake 泥饼mud weight(density) 泥浆重量（密度）viscosity 粘度filtrate 滤液water loss 失水gel initial 初切力gel strength 静切力solid control equipment 固控设备shale shaker 振动筛desander 除砂器desilter 除泥器centrifuge 离心机screen cloth 筛布ply 层mesh （筛布）目PH 酸碱值mud pit 泥浆池MBT=methylene blue test 亚甲基蓝测定法KCL氯化钾lime 石灰SAPP=sodium acid pyrophosphate 粒状焦性磷酸钠NaOH氢氧化钠，烧碱mud tank 泥浆罐mud gun 泥浆枪trip tank （起下钻）泥浆计量罐active tank 上水罐，在用罐intermediate tank 过渡罐GPM =gallon per minute 加仑/分钟1 US gallon 美加仑=3.785 liters 升1 barrel 桶=0.159 cubic meters 立方米1 SG(比重)X8.33=1 ppg 磅/加仑二.阅读练习1.固控设备评价和建议Performance of Solid Removal Equipment In RIG 5003 & Recommendations Prepared byAmmar A.MaroufDrilling Fluids Engineer50003队固控设备的性能特点和建议IntroductionThe types and quantities of solids present in drilling mud systems determine the fluid density , viscosity , gel strengths , filter cake quality and filtration control , and other chemical and mechanical properties > Solids and theirs volumes also influence mud and well costs , including factors such as , rate of penetration , hydraulics , dilution rates , torque and drag , surge and swab pressures , differential sticking , lost circulation , hole stability , and bit balling , these in turn , influence the service life of bits , pumps and other mechanical equipment .Chemicals , clays and weighting materials are added to drilling mud to achieve viarious desirable properties. Drill solids , consisting of rock and low –yielding clays , are incorporated into the mud . These solids affect many mud properties adversely . Nevertheless , since it is not possible to remove all drill solids either mechanically or by other means – They must be considered a continual contaminant of a mud system .Solid removal is one of the most important aspects of mud systems control , since it has a direct bearing on drilling efficiency . Money spent for solids control and for solving problems related to drill solids represents a significant portion of overall drilling costs . Solid control is a constant problem every day . on every well.FundamentalsDrilling mud solids may be separated into two categories: Low Gravity Solids (LGS) with Specific Gravity in the 2.3-2.8 range , and High Gravity Solids (HGS) with SG of 4.2 or higher . Weighting materials such as Barite or Hematite comprise the HGS category and are used to achieve densities greater that 10 PPG . Drill solids , clays and most other mud additives fall into the LGS category and often ate the only solids used to obtain densities up to 10 ppgOne of the primary uses for drilling fluids to carry unwanted drilled solids from the borehole. The solid s are essentially a contaminant and, if left in the mud, it can lead to numerous operational problems. Three options to maintain drilling fluid properties∙Do nothing and let the solid build up. When the mud no longer meets specification, dump it and start with fresh mud.∙Dilute the mud and rebuild the system to keep the properties with acceptable ranges, while dumping excess mud to the reserve pit.∙Lower the solid content of the mud through solids removal equipment to minimize the addition/dilution necessary to maintain acceptable properties.In recent years, increased public awareness of environmental issues has provided both regularly and economic incentives to minimize drilling waste. In many instances, the first two choices have become very expensive and unacceptable. This has served to stress the importance of the third option, efficient solid control. Using solids control equipment to minimize addition/dilution volumes is normally most effective and provide the following benefits:❑Lower water requirements and Less mixing problems❑Increased penetration rates Reduced torque and drag❑Lower ECD & Reduced system pressure losses❑Better cement jobs and Reduced formation damage❑Less differential sticking❑Reduced environmental impactIt is apparent from this list that the role of solid control is instrumental in the maintenance of good drilling fluid. Although the benefits from good solids control are numerous, the cost savings are not appear in normal drilling cost accounting.Usually the drilling fluid gets most of the credit (or blame) since mud material consumption is easily tracked and the mud properties are the only direct indication of solids control performance. In realistic sense, the mud and the solids control equipment are integral part of one system. One cannot plan the mud without considering the solid control system and vice versa.Solid control is accomplished by using one or more of the basic methods of solid separation :-SettlingScreeningHdrocyclonesRotating CentrifugesHydocyclones and centrifuge use centrifugal force to obtain higher rates of Separationthan can be achieved by gravitational settling . These method are governed by well-known laws of physics . If the mud kept moving so that the gel strength broken , then the settling of particles is governed by strokes Law which isVs = g c D s(q s-q t)/ 46.3uThe equation is a mathematical expression of events commonly observed , i.e, the larger thedifference between the density of the solid and the density of the liquid q s-q tthe faster the solid will settle , and the lower the fluid viscosity (u) the faster solid will settle . beside the influence of the force action gc which will increase the settling rate .Shale shakerThe most important solid control devices are shale shakers , which are vibrating screen separators used to remove drill cuttings from mud . It has proven to be a simple and reliable method of moving large amount of coarse, drilled cuttings from circulating system. As the first step in the mud cleaning /solids –removal chain , they represent the first line of defense against solids accumulation . Shale shakers differ from the other solids removal equipment in that they produce nearly a 100% cut ( D100) at the screen opening size .A 200 –square mesh shale shaker screen will remove 100% of the solids greater than 74 micron , thereby eliminating the needs for a Desander . Also the shakers provide the advantage of reducing solids loading to the down stream hydocyclones to improve their efficiency beside no t degrading soft or friable cuttings. When well –operated and maintained, shale shakers can produce a relatively dry cuttings discharge.Enough shakers should be installed to process the entire circulating rate with the goal of removing as many drilled cuttings as economically feasible. Unless the shale shakers are operating properly , and have screens of the finest mesh possible , all other equipment is subject to overloading and inefficient operation . Shakers cannot remove silt and colloidal –size solids , so dilution and other equipment is required to control ultra-fine drill solids .HydrocyclonesHydrocyclones are a-cost effective method of removing many of fines solids missed by the shaker in unweighted muds. A centrifugal pump feeds a high – volume mud through a tangential opening into the large end of the funnel – shaped hydrocyclone . when the proper amount of head ( Pressure ) is used , this results in a whirling of the fluid much like the motion of water spout , tornado or cyclone expelling wet ,higher mass solids out the open bottom while returning the liquid through the top of the hydocyclone , so all the hydocyclone operate in a similar manner , whether they used desnder or desilter .In some formations, the solids are too fine for the shakers to remove; hydocyclones must be relied upon to remove the majority of the solids. In these instances, the shaker protects the hydro cyclone from oversize particles, which may cause plugging. Because the hydocyclone has no moving parts, it can be very reliable pieces of solids removal equipment when correctly operated and maintained.Hydocyclones separate solids from fluid by using centrifugal force to cause solids to be settled from the fluid. There are no moving parts. Centrifugal force is created by the conversion of centrifugal pump head into high velocity stream spiraling within the cone.Oil field hydrocyclone are available in cone diameters ranging from 1 in to 12 in . Hydro cyclones were first used to reduce API sand content (Solid larger then 74 microns). Hence the term ―Desander‖ . By convention, hydrocyclones with diameters of 6 in. or larger are labeled as Demanders. As the benefits of smaller, more efficient Hydocyclones became apparent, the term Desilter was coined to reflect the sma ller ―silt-sized‖ particles, these smaller cones could remove. Hyrocyclones with diameters of less than 5 in are usually called Desilter . However, these terms are not based on any particular performance standard.The primary role of the Desander should be to reduce solids loading to the Desalted cones. It recommended when the shakers are unable to screen down to 100 microns or when large hole diameters are drilled at 100ft/hr or faster. Ten-inch diameter Desander cones are recommended. They provide combination of separation and capacity. The larger 12-in cones usually cannot make a fine enough cut to be economic. Desilter should be used on all un-weighted water based mud . They are recommended for use on weighted muds since barite will be lost . When using expensive mud , process the desilter underflow with a centrifuge.Mud CleanerBasically , a mud cleaner is a desilter mounted over a vibrating –screen shaker generally 12 or more 4 in . hydrocyclones above a very fine mesh screen , high energy shaker . A mud cleaner will remove sand size drill solids from the mud , yet retain the barite . it first processes the mud through the desilter , then screens the discharge through a fine mesh shaker .A mud cleaner , in effect , desands a weighted mud and it is aback up to the shale shakers . mud cleaner screens vary in size from 120 mesh to 325meshCentrifugeAs with hydrocyclones , decanting –type, centrifuge increase the forces causing separation of the solid by increasing centrifugal forces . The decanting centrifuge consists of a conical , horizontal steel bowl rotating at high speed , with screw –shaped conveyor inside . the conveyor rotates in the same direction as the outer bowl , but slightly slower speedEvaluation of Solid removal equipment Condition in RIG 50031.Shale ShakerNo. of Units - 3Made DerrickScreen Size - 140 x 110 x 84 mesh (Pyramid Type)Performance - Fairly good at mud density up to 1300 kg/m3.2. DesanderNo. of Unit - One(1)Type - Two(2) ConesMade - ChinaPerformance Very poor, with only one(1) cone can be operated at a time to attain the desired feed pressure.Efficiency - 3.7 % (Solids Removal). Feed Mud Wt - 1220 kg/m3,Overflow - 1215 kg/m3Underflow - 1260 kg/m3.(% removal = [(1260-1215)/1215 x 100.]Underflow Discharge Rate - 0.3 to 0.4 m3/hour.3. D esilterNo. of Unit - One (1)Type - Twelve (12) ConesMade - SWACO ( Plastic Cones made in China)Performance Very poor, with only eight (8) cones operating. Other cones were plugged intentionally due to big nozzle area and causing too much discharge.Efficiency 9.5 % (Solids Removal). Feed Mud Weight - 1220 kg/m3, Overflow -1215 kg/m3Underflow - 1330 kg/m3.( % removal = [(1330-1215)/1215 x 100]Underflow Discharge Rate = 0.6 to 0.8 m3/hour.4. C entrifugeNo. of Unit - One (1)Type - High SpeedMade - ChinaPerformance- Fairly Good but discharges both Barite and drilled solids.Efficiency 81 % (Solids Removal) at 20 - 25 gallons/minute. If Feed MudWeight - 1220 kg/m3,Overflow Weight - 1160 kg/m3,Underflow(all solids) - 2100 kg/m3.% Removal = [(2100 - 1160)/1160 x 100]Observations1. O nly one (1) feed pump is used for both the Desander and Desilter. The other feed pump isnotused due to high leakage of mud on the pump. There is no appropriate packing on site to seal off the leak.2. P ressure gauges on both Desander and Desilter are not working.Conclusion & RecommendationThe shale shakers installed on Rig 5003 are Derrick shakers, the screen sizes can be used is 84, 110, 140 , 175 mesh . The deck angle can be hydraulically adjusted which will improves control flow rate and solid dryness , also eliminates (Pooling ) and back spill of expensive barite with higher degree of adjustment also the proper adjustment of the vibrator angle will help in improving control of conveying speed and ideal for high solid loading specially during drilling the surface hole or when the drilling rates slow s near TD and finer cuttings are being separated . In general all the three Shakers are working good , Just some adjustment required for the vibrator angle for more separating efficiency .Recommendation for proper Operation of shale shakers1- Mount and operate the shaker in a level conditionBoth the solids and volume capacities will be reduced if a shaker is not level2- Provide the proper voltage and frequencyLow voltage reduces motor life , and low frequency reduces the vibrating motion and capacity .3- Be certain the vibrator is rotating in the proper direction for proper solid discharge4- install the proper screen support cushion in accordance with the manufactures directions ( screens that rub against steel rapidly wear out )5- Take special care to tension screens properly in accordance with the manufactures recommendations ( for more life)6- screens should be sized such that the mud will cover 75 to 80 % of the area7- With multiple deck shakers , the proper combination of screens sizes should be used .8- A water or oil hose should be provided to wash down the screens .9- A water or spray is occasionally used on the screens to assist the removal of sticky particlesHydrocycloneThe Desander condition is poor , one cone is working and the other is dumping mud more than separating solids . The Desilter performance is very poor, with only eight (8) cones operating. Other cones were plugged intentionally due to big nozzle area and causing too much discharge.On the other hand there is only one (1) feed pump is used for both the Desander and Desilter. The other feed pump is not used due to high leakage of mud on the pump. There is no appropriate packing on site to seal off the leak.Both of Desander and Desilter should be inspected prior start drilling the ne xt exploration well , Changing the washed cones is highly recommended for both to minimize the discharge rate and to maximize the separation efficiency , beside we strongly recommend to install another feed pump for the Desilter other pump should be checked and inspected, this was help in reclaiming the mud from the fine solids and keeping the solid content as lowest possible. Installing a mud cleaner is highly recommended if more explorations wells will be drilled . This is to save time which means s aving money .Maintenance and Trouble shooting of Desander & Desilter1- No wet solids discharge at the apex ( Bottom)One) b ottom opening plugged : Turn unit off . Lossen bottom adjustment . Push a rod up through the bottom opening to break up the drilled or caked mud , if this is not successful , remove the top of the hydrocyclone and make out object plugging apex .Two) f eed pressure (head ) too high : adjust to proper head pressure ,or 75+_ ft using accurate pressure gauge .Three) Mud cleaned of all particles hydrocyclone can remove : shut down or run it periodically2- Flooding liquid out of apex ( bottom)One) f eed pressure too lowTwo) h ydrocyclone inlet plugged resulted in inadequate feed pressure Three) Vortex finder plugged , resulting in back – pressure on hydrocyclone3- Hydrocyclones plugging One) feed header plugged Two)Hydrocyclone overloadedCentrifugeThe centrifuge working well and it was run intermittent , so as to avoid strip too much barite from the system.Recommendation for proper Operation of shale Centrifuge :1- Do not operate the centrifuge without the rotating assembly shroud and belt guards , fastened inplace2- Rotate the bowl by hand first to ensure ―free‖ movement . 3- Do not operate if unusual noise or vibration develops .4- Allow the units to attain desired rotational speed prior to starting the feed pump. 5- Do not overfeed ―crowd‖ the centrifuge .6- Heavily weighted and viscous fluid require lower feed rates and higher dilution rates7- Ensure proper agitation is available at the centrifuge pump suction and in the barite return tank.2. 腐蚀环测试报告腐蚀环是用于评价钻井液腐蚀性的一种方法，通常预先称出其重量，然后分别在钻铤和钻杆之间及方钻杆下部各放置一个，在井下与钻井液接触一段时间（不少于50小时）后，取出腐蚀环称重、检测，获得钻井液的腐蚀性和腐蚀特征。
