【正文】 系?？傊?，使用螺桿鉆具不對所匹配的鉆頭進(jìn)行認(rèn)真選擇，要想取得滿意的效果是困難的，還會造成鉆具過早地?fù)p失。 5． 5 對井底環(huán)境溫度的要求：溫度過高對鉆具馬達(dá)性能十分不利，會使所有不利 因素加劇。使用油基泥漿液，井底溫度低于 95 C，鉆具工作狀態(tài)最佳。當(dāng)溫度超過 150 C時，即使使用最佳的油基鉆井液，甚至使用水基鉆井液，鉆具定子壽命也會大幅度縮短。 為使鉆具在較高的油基鉆井液下正常工作，可以采用分段下鉆，間歇循環(huán)，使用帶分流孔的空心轉(zhuǎn)子，以加速循環(huán)或改善鉆井液的散熱性及其它性能的方法。保證實(shí)際定子工作溫度低于極限值。 我公司生產(chǎn)兩種定子。一種是普通定子，額定溫度為 95 C，最高溫度 120 C。一種是耐高溫定子，額定溫度 105 C，最高溫度 150C。 5． 6 對鉆井液流量的要求：螺桿鉆具特點(diǎn)之一，輸出轉(zhuǎn)速與輸入鉆井液流量成正比。每種鉆具都有一定 C: PDC Bit: It is not only used for directional deflection, and also more appropriate to longer drilling period, such as vertical well drilling. During longer period of drilling operation, the more important factor is to integrate bit and screw drill. It is to avoid unnecessary trip operation due to some problem. It is known that PDC bit can last longer time than rock bit, and it is integral in structure, having more advantages. D: It is also an important factor to prolong running life of bit and tool. It is helpful to extend screw life and to develop bit property by improving stability of drive shaft, . stabilizer. And it shall be considered the close relationship between diamond geometric dimension, allocation , drilling weight load and the required high speed and lower drilling weight of downhole tool. In general, it is hard to obtain satisfactory effect without strictly matching bit and screw drill, it can also cause earlier damage onto the tool. Requirement for Hole Bottom Temperature: It is unfavorable to the motor property, and it may intensify all disadvantageous factors if temperature goes too high. When using oil base mud, the hole bottom temperature shall be lower than 90176。C, screw drill shall be working in optimum condition. When temperature is over 150176。C, stator life may be greatly shortened, even by using optimum oil base mud or using water base mud. In order to keep screw drill working normally at high temperature of oil base mud, the way shall be adapted to conduct tripin by sections and intermittent recycling , to ensure the actual temperature of stator below the ultimate value by using hollow rotor with splitter hole to speed up recycling or improve heat radiation of the fluid and other property. Our pany manufacture two kinds of stators. One is conventional stator, with 95176。C of rated temperature and 120176。C of maximum temperature。 another is hitemperature stator, with 105176。C of rated temperature and 150176。C of maximum temperature. Requirement for Flow Rate of Drilling Fluid: One of the screw drill features is that the output speed is proportional to the input flow rate of drilling fluid. Each screw drill has a certain effective range of working flow 上海奧森油田服務(wù)有限 公司 Shanghai Ocean Oilfield Service Co. Downhole Motor 10 的有效工作流量范圍，建議按推薦參數(shù)進(jìn)行選擇，否則會降低鉆具的工作效率和使用壽命。 5． 7 鉆井液壓力與鉆壓的特點(diǎn)：鉆具進(jìn)行空運(yùn)轉(zhuǎn)時，若保持泥漿流量不變，鉆具與鉆頭的壓降為一個常數(shù)，該值隨鉆具型式和規(guī)格的不同而有所不同。鉆具工作時，隨著鉆壓逐步增加，鉆井液循環(huán)壓力逐漸上升，該壓力的增量與鉆壓或鉆進(jìn)所需扭矩的增量成正比，當(dāng)達(dá)到最大推薦值時，產(chǎn)生最佳扭矩。繼續(xù)增加鉆壓，當(dāng)循環(huán)鉆井液在馬達(dá)兩端產(chǎn)生的壓降超過最大設(shè)計(jì)值時，鉆具將發(fā)生泄漏。正常工作時，表壓隨鉆壓的增減而升降。如果泵壓表突然增加了幾兆帕，繼續(xù)增加鉆壓 ，泵壓不再增加，這說明鉆具發(fā)生了泄漏，此時鉆具定子與轉(zhuǎn)子間密封破壞，鉆井液通過破壞的馬達(dá)密封腔從鉆頭水眼中流出。當(dāng)因故障卡鉆時，鉆井液在鉆具制動情況下，仍可以繼續(xù)循環(huán)流過鉆具。一旦鉆具發(fā)生制動，應(yīng)迅速將鉆具提離井底降低鉆壓，因?yàn)殂@井液長時間流過不轉(zhuǎn)的馬達(dá)會使鉆具嚴(yán)重?fù)p壞。 另外，要使鉆具獲得最佳工作效率，應(yīng)將鉆具兩端的壓差控制在推薦參數(shù)范圍內(nèi)。 5． 8 預(yù)先進(jìn)行必要的水利計(jì)算：鉆井作業(yè)時，由泥漿泵泵出的鉆井液依次經(jīng)立桿、水龍頭、方鉆桿而進(jìn)入鉆桿、鉆鋌、無磁鉆鋌、鉆具（馬達(dá)）、鉆頭水眼及環(huán)空而返回地面。在鉆井液不斷循環(huán)過程中，由于鉆井液本身的摩擦和鉆井液與 管壁、 rate. It is advised to choose the range according to the remended parameters. Otherwise, it may shorten the screw drill’s working efficiency and running life. Features of Drilling Fluid and Drilling Weight: When screw drill is in idle working condition, if keeping fluid flow rate unchanged, the pressure loss caused by both bit and screw drill shall be a constant value. This value changes with the difference of drill model and specification. As screw drill is running, fluid recycling pressure will gradually increase with gradual rise of drilling weight. The increment of pressure is proportional to the torque increment needed by drilling weight and stripping in. When it reaches the maximum remended value, optimum torque shall be produced. If drilling weight goes on rising, when the pressure loss of recycling fluid at both ends of motor is over maximum design value, leakage shall occur from the screw drill. In normal operation, the gauge pressure rises with the drilling weight up and down. If the gauge shows sudden rise of temperature to several Mpa, when the drilling weight goes on increasing, pump pressure shall no longer increase. This indicates there occurs some leakage from screw drill. The seal between stator and rotor may be changed, and fluid may be flowing out from bit nozzle while going through the damaged seal cavity. When it is sticking due to this problem, fluid is still recycling through screw drill since screw drill braking. Once screw drill brakes, it shall be quickly lifted away from the hole bottom to reduce drilling weight, since screw drill may be seriously damaged with fluid flowing through the idle motor for longer time. Additionally, the pressure loss at the bottom ends of screw drill shall be controlled within the remended range, to ensure screw drill in optimum working efficiency and running life. Early Hydraulic Calculation: In drilling operation, the pumped mud flows successively through riser, swivel, kelly into drill pipe, collar, nonmagic collar, motor ,bit nozzle and annular space, and upwards to the surface. During recycling, the loss caused from the friction of fluid its own and the friction of fluid onto the pipe wall, hole wall and/or partial flow will consum