本文選題：地層平均壓力　切入點：試井分析方法　出處：《中國地質(zhì)大學(xué)(北京)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：試井是評價油氣藏開發(fā)動態(tài)的重要技術(shù)方法和基礎(chǔ)工作之一。壓恢試井是目前常用的一種方法,通過MBH曲線等計算出地層平均壓力等。地層平均壓力可以用來預(yù)測油藏未來動態(tài)、計算原始地質(zhì)儲量以及描述油氣藏特性,在一次開采、二次開采和壓力保持過程中,評價油藏動態(tài)和井工作狀況具有十分重要的作用。本文給出了正六邊形、矩形地層、直角三角形、正三角形、菱形一口井的鏡像反演方法,反演后再應(yīng)用疊加原理就很容易求得地層的壓力分布以及產(chǎn)能公式,同時可以用此方法得出不同規(guī)則幾何形狀的MBH函數(shù)。通過對Russell的圓形封閉油藏一口井的壓力恢復(fù)解析式進(jìn)一步推導(dǎo)嚴(yán)格證明了Muskat等人經(jīng)驗結(jié)論的正確性,并用實例驗證其具有較高的精度。根據(jù)地層平均壓力的定義,對不穩(wěn)定滲流控制方程組進(jìn)行積分,或者積分對應(yīng)的壓力分布函數(shù)(控制方程組的解式),求取圓形封閉油藏壓力降落過程中的地層平均壓力的變化規(guī)律。兩者的結(jié)果一致。運(yùn)用疊加定理,求取圓形封閉油藏壓力恢復(fù)過程中的地層平均壓力變化規(guī)律。隨著壓恢時間的增大,地層平均壓力逐漸增大,但變化減慢,恢復(fù)到一定程度保持不變;生產(chǎn)時間越長,相應(yīng)的地層平均壓力越小。根據(jù)地層平均壓力的定義,對不穩(wěn)定滲流控制方程組進(jìn)行積分,并運(yùn)用格林定理求取常規(guī)氣藏平均壓力變化規(guī)律。早期不穩(wěn)定流動階段,平均壓力為一重合的曲線,隨時間的增大,平均壓力逐漸減小,隨著邊界范圍的增大,邊界流發(fā)生時間越晚。當(dāng)壓力波傳到邊界之后,由于地層是封閉的,此時整個地層壓力都下降,井的產(chǎn)量完全來源于壓力下降引起的流體和巖石體積膨脹而釋放的彈性能,經(jīng)過一段時間后,地層各處的壓力降落速度相同,都等于泄流區(qū)內(nèi)平均壓力降落速度,達(dá)到擬穩(wěn)態(tài)滲流。根據(jù)地層平均壓力的定義,對不穩(wěn)定滲流控制方程組進(jìn)行積分,并運(yùn)用萊布尼茨公式求取低滲透儲層平均壓力變化規(guī)律。隨著時間的增大,地層平均壓力逐漸減小,且變化減慢;啟動壓力梯度越大,到達(dá)物理邊界越晚;到達(dá)邊界后,地層平均壓力與時間呈線性關(guān)系。啟動壓力梯度越大,地層平均壓力越小。
[Abstract]:Well testing is one of the important technical methods and basic work for evaluating the development performance of oil and gas reservoirs. The average formation pressure can be used to predict the future performance of the reservoir, calculate the original geological reserves and describe the characteristics of oil and gas reservoir. It is very important to evaluate reservoir performance and well working condition. In this paper, a mirror image inversion method for hexagon, rectangular formation, right triangle, regular triangle and diamond well is given. After inversion, the pressure distribution and productivity formula of the formation can be easily obtained by applying the superposition principle. At the same time, the MBH function with different regular geometry can be obtained by this method. The accuracy of the empirical conclusion of Muskat et al is proved strictly by deducing the pressure recovery analytic formula of a well in a circular closed reservoir of Russell. According to the definition of average formation pressure, the governing equations of unstable seepage flow are integrated. Or the pressure distribution function corresponding to the integral (the solution of the governing equations, the law of the variation of the formation average pressure during the pressure drop of the circular closed reservoir) is obtained. The results of the two methods are consistent, and the superposition theorem is used. With the increase of pressure recovery time, the formation average pressure increases gradually, but the change slows down, and the recovery to a certain extent remains unchanged; the longer the production time, the longer the formation average pressure is. According to the definition of average formation pressure, the governing equations of unstable seepage flow are integrated, and the law of average pressure variation in conventional gas reservoirs is obtained by using Green's theorem. The mean pressure is a coincidence curve. With the increase of time, the average pressure decreases gradually. With the increase of the boundary range, the boundary flow occurs later. When the pressure wave reaches the boundary, the formation is closed. At this point, the whole formation pressure is reduced, and the production of the well is completely derived from the elastic energy released by the volume expansion of the fluid and rock caused by the pressure drop. After a period of time, the pressure drop rate throughout the formation is the same. According to the definition of average formation pressure, the governing equations of unstable seepage flow are integrated. With the increase of time, the average formation pressure gradually decreases and the variation slows down. The bigger the starting pressure gradient is, the later it reaches the physical boundary, and the later the formation pressure reaches the physical boundary after reaching the boundary. The average formation pressure is linearly related to time, and the larger the starting pressure gradient is, the smaller the formation average pressure is.
【學(xué)位授予單位】：中國地質(zhì)大學(xué)(北京)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TE271

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

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本文編號：1604174