硫化氢防护.docx

7.6 Hydrogen Sulphide (H2S) Prevention7.6硫化氢防护7.6.1 H2S Sources During Drilling Hydrogen sulphide (H2S) may present in reservoir fluids in the operated wells. There are a number of possible sources of H2S in well fluids, the most common sources are:- Drilling fluid additive decomposes under high pressure and temperature.- Function of bacteria in the drilling fluid.- During drilling into formation containing H2S, a lot of H2S enters into well. H2S gas field often exists in carbonate sand, especially in the sediment environment of carbonate sand associated with sulphate. Generally speaking, the content of H2S increases with the depth.7.6.1钻井过程中硫化氢来源硫化氢（H2S）可能会出现在作业井中的储层流体中。流体中有几种潜在的硫化氢来源，最常见的硫化氢来源是：- 某些钻井液处理剂在高压高温下分解；- 钻井液中细菌的作用；- 钻入含H2S地层，大量H2S侵入井中，H2S气田多存在于碳酸盐岩地层中，尤其在与硫酸岩伴生的碳酸盐沉积环境中，H2S更为普遍。一般地讲，H2S含量随地层埋深增加而增大。7.6.2 Hazard of H2SHydrogen sulfide is a highly toxic, colorless gas, heavier than air, with the odor of rotten eggs. If ignited, it burns with a blue flame and produces sulfur dioxide, which is a very irritating gas with a pungent odor. H2S forms explosive mixtures with air, the lower explosive limit is 4.3% hydrogen sulfide, and the upper explosive limit is 46.0%. During drilling operations, the consequences of H2S leaks can be very serious. Personnel can be incapacitated by relatively low concentrations of H2S in a very short time and equipment can suffer catastrophic failure due to H2S embrittlement.7.6.2 硫化氢危害H2S是一种剧毒、无色、比空气重且具有臭鸡蛋气味的气体、若点燃将产生蓝色火焰，并生成SO2，它也是一种具有刺激味的有毒气体，H2S与空气混合形成爆炸性气体，爆炸下限为4.3%，上限为46.0%。在钻井过程中，硫化氢的溢出可能导致严重的结果。低浓度的H2S也会在很短时间内使人失去知觉，设备也会因H2S的脆化（氢脆）而出现灾难性故障。7.6.2.1 Hazard of H2S on PersonH2S is generally recognized by a characteristic foul, rotten egg odor. Prolonged exposure to low concentrations will dull the sense of smell. This can be fatal to those who think they can detect dangerous concentrations by the offensive odor. It acts on the eyes and respiratory system, resulting in irritation. Irritation to the eyes often causes severe pain and may incapacitate the worker. When high concentrations are present, death, due to lung paralysis, may occur before the odor is detected.7.6.2.1硫化氢对人体的危害一般用H2S具有恶臭和臭鸡蛋气味的特性来识别，但与低浓度的H2S的接触时间过长，将使嗅觉迟钝。对那些自认为能通过刺激性气味来检测危险浓度的人来说是致命的。它还对眼睛和呼吸系统具有危害，对眼睛的刺激经常会导致严重的疼痛感，并可能会使人失去知觉。当在高浓度的H2S下，在你闻出气味之前，即可能由于肺呼吸麻痹，导致死亡。 See below toxicity table of H2S请见下面的不同浓度硫化氢对人体的危害数据表Toxicity Table of H2S不同浓度硫化氢对人体的危害数据表Concentration of H2S硫化氢浓度Effects and Required Response危害和要求的反应ppmMg/m311.5A strong smell of rotten egg. 可嗅到一种明显的臭蛋气味。1015Safe for 8 hours exposure.可在暴露的环境中安全工作8小时。2030Protective equipment will be necessary.必须穿戴防护用品。100150Kill sense of smell in 3 to 15 minutes, and burn eyes and throat. 315min可抑制嗅觉，能刺痛眼和喉道。200300Kill sense of smell quickly, and burn eyes and throat.很短时间内就抑制嗅觉，刺痛眼和喉道。500750Individual loses sense of reasoning and balance. Respiratory paralysis occurs in several minutes. Requires prompt artificial resuscitation.失去判断和平衡能力，几分钟内呼吸麻痹，需立即作人工呼吸。7001050Breathing will cease and death if not rescued promptly and immediate artificial resuscitation applied. 很快就昏迷，若不立即作人工呼吸将导致死亡。10001500Individual is unconscious immediately, permanent brain damage may result if not rescued immediately立即不省人事，若不立即清酒，会造成永久性脑损伤。7.6.2.2 Hazard of H2S on MetalH2S dissolves in water to form a weak acid that can cause pitting of metal, when it is in a mixture of oxygen or carbon dioxide, this reaction is increased. The most significant reaction is hydrogen embrittlement or known as sulfide stress cracking. Sulfide stress cracking is a result of metals being subjected to high stress in a corrosive environment where hydrogen sulfide is present. The metal will often fail in a brittle manner. 7.6.2.2硫化氢对金属材料的危害H2S溶在水中将形成一种弱酸，它能使金属出现麻点状腐蚀，当它与氧气或二氧化碳混合时，这种反应将加快。H2S最明显的反应是氢脆，或称为硫应力裂纹，硫应力裂纹是金属在H2S存在的腐蚀环境中受到高应力的结果，金属变得很脆。7.6.3 Layout of Well Site in Sulfurous Gas FieldInformation regarding prevailing seasonal wind direction should be obtained from local meteorological information before drilling commence.7.6.3含硫气田井场布置钻前工程施工前，应从气象资料中了解当地季节风的风向。Prevailing wind should be taken into consideration when installing drilling equipment. Space around the well site should be clear for the seasonal wind to pass by. 井场及钻机设备的安放位置应考虑季节风风向。井场周围要空旷，尽量在前后或左右方向能让季节风畅通。Doghouse, office and drilling fluid laboratory should be located upwind.井场值班室、工作室、钻井液室等应设置在井场季节风的上风方向。Wireline logging unit and other mobile vehicles should be as far away from the bore as possible with a distance of at least 25 m.测井车等辅助设备和机动车辆，应尽量远离井口，至少在25m以外。Wind socks shall be put on such places as the mast, the entrance of wind to well site. Once there is any emergency, e.g. H2S concentration exceeding critical concentration, crew members shall scatter to upwind places.在井架上、井场季节风入口处等地应设置风向标。一旦发生紧急情况（如硫化氢浓度超过安全临界浓度），钻井人员可向上风方向疏散。At the place where H2S is easy to concentrate such as drilling floor and shale shaker, ventilation fans shall be installed to disperse H2S content all over the well site.在钻台上下，振动筛等硫化氢易聚积的地方，应安装排风扇，以驱散工作场所弥漫的硫化氢。50m before drilling into the gas formation, the wind protecting shield and other similar things on monkey board shall be removed. 进入气层前50m应将二层台设置的防风帆布和其它类似围布拆除。Make sure communication is in good condition. 确保通讯系统畅通。7.6.4 Special Requirement in H2S Wells7.6.4 含H2S井的特殊要求All zones known to contain or suspected to contain H2S are to be noted on the drilling program.所有认为含有H2S气体或怀疑含有H2S气体的区域都应在钻井设计中做出说明。All tubular goods, wellhead equipment, and other drilling equipment which may be exposed to H2S during the course of operations, are to be selected, considering the metallurgical properties which will reduce the chance of failure.对于在使用中可能接触H2S气体的所有管状部件，井口设备和其它钻井设备，在选择时应考虑它们的金属性能，以减少事故的发生机会。To minimize intrusion of H2S into the wellbore, drilling mud weight should be controlled at a level to prevent gas intrusion.为了减少H2S气侵，应当把钻井泥浆重量控制到防止气体侵入的水平上。Drilling program should include the use of a H2S scavenger in the drilling fluid system to reduce the reaction of H2S on the drill string, mud pumps, chokes, and piping. Scavengers can also reduce the amount of hydrogen sulfide reaching the surface. 钻井设计中应包括在钻井液中使用H2S清除剂，从而降低H2S对钻柱，泥浆泵，节流管汇和管道的化学反应，它也能减少H2S到达地面的数量。The pH of the drilling fluid should be maintained above 9.5 at all times. In some cases, the pH value higher than 11.5 is required to prevent a reduction in the pH below 9.5 while making a trip with the drill string.钻井液的PH值任何时候必须大于9.5，在一些情况下，要求PH值大于11.5，以防PH值在起下钻管柱时低于9.5。Every effort should be made to pull drill string dry. If it is necessary to pull the string wet after penetration of H2S bearing zone, close monitoring of the working area should be provided and protective breathing apparatus should be on standby if necessary.要尽一切努力使提出的钻具保持干燥。如果在钻入含H2S地层时需要将钻具湿着提上来，要对工作区域进行密切监测，并准备好呼吸装置以备使用。Breathing apparatus should be worn by personnel in the working area prior to circulating bottoms-up. if H2S is indicated in sufficient quantities.如果H2S显示明显，工作区域的人员要在井底泥浆循环上来之前戴上呼吸装置。Breathing apparatus should be worn by personnel on the drillfloor from 10-20 stands in advance of retrieving the core barrel and especially while the cores are being removed from the core barrel. Cores should be sealed and marked indicating the presence of H2S before transportation.在上提取芯筒并离钻台10-20个立柱时，特别是当岩芯从取芯桶取出时，钻台上的人员要戴呼吸装置。在装运之前，将岩芯密封，并标出此岩芯含H2S情况。7.6.5 H2S Detection 7.6.5 H2S的监测Rig site shall have sufficient H2S detection systems. The type and number of detection units should be decided based on the local conditions, the type of operation and the local laws and regulations.井场必须配备充足的H2S监测系统。监测设备的种类和数量应根据现场情况、作业类型以及当地的法律法规来确定。Fixed H2S gas detection system should consist of a visual and an audible alarm. The gas detectors should be located where there is the greatest potential to detect H2S:- Bell nipple- Drillers console- Mud tanks- Shale shaker - Well cellar固定式H2S气体检测系统应包括声、光报警功能。安放在最容易检测到H2S的地方：- 喇叭口- 司钻控制台- 泥浆罐- 振动筛- 圆井Certain numbers of portable H2S meters should be used. Refer to appendix 7 Guideline of Emergency Response Plan for detailed information regarding the allocation of detection system.- 应在井场上配备一定数量的便携式H2S检测仪。具体检测仪器的配备的详细要求请参见附件7应急预案指南。The warning alarm(s) shall be generated automatically when the H2S concentration exceeds the permissible exposure limit (10ppm), the alarms should be divided into 3 levels:- The first level alarm should be set at 10ppm (permissible exposure limit)- The second level alarm should be set at 20ppm (safe threshold limit)- The third level alarm should be set at 100ppm (dangerous threshold limit), the alarm signal should be clearly discriminate from the first and second level alarms.H2S报警系统必须在空气中H2S含量超过10ppm时自动报警，设置的报警应划分为3个等级：- 第一级报警值应设置在10ppm （允许暴露阈限值）- 第二级报警值应设置在20ppm （安全临界浓度值）- 第三级报警值应设置100ppm （危险临界浓度值），其报警信号应与一级和二级报警信号有明显区别7.6.7 Breathing Apparatus7.6.7 呼吸器Personnel working in H2S area must carry a positive pressure breathing mask.在存在H2S的空间内作业的人员必须携带正压式呼吸面具。A plan shall be prepared for the requisite number of breathing apparatus in addition to a precise description of the location of each unit. This type of equipment should be located strategically so that they can quickly be reached by all personnel involved if an emergency occurs.要对呼吸器的数量和每个呼吸器的放置地点做出详细的描述。这些呼吸器应放置在非常关键的地方，以便在出现紧急情况时，所有相关人员都能够迅速地拿到。All breathing apparatus shall be worn and used according to the manufactures specifications. During evacuation, the external air supply shall be disconnected, and there shall be sufficient compressed air within the breathing apparatus which could last for a minimum of 30 minutes. 必须按照生产厂家用户手册的要求穿戴和使用所有的呼吸器。在撤离的过程中，外部气源必须断开，同时必须保证呼吸器内有足够的压缩空气以维持至少30分钟的呼吸用气。All breathing apparatus shall be c