本文選題：低滲碳酸鹽巖油藏 + 可動流體��； 參考：《中國科學(xué)院研究生院(滲流流體力學(xué)研究所)》2015年碩士論文

【摘要】：低滲碳酸鹽巖油藏是我國在海外油氣開發(fā)的重要油藏類型,該油藏儲層微觀孔喉結(jié)構(gòu)復(fù)雜,與低滲砂巖油藏有明顯的差異,急需進(jìn)行低滲碳酸鹽巖油藏儲層評價方面的研究工作。由于低滲碳酸鹽巖油藏孔洞縫發(fā)育非常復(fù)雜,常規(guī)儲層評價的實(shí)驗(yàn)方法很難準(zhǔn)確的對其評價。本文通過恒速壓汞實(shí)驗(yàn)、核磁共振實(shí)驗(yàn)、啟動壓力梯度測試和油水兩相滲流規(guī)律實(shí)驗(yàn)對A油田Sadi、Tanuma、 Khasib和Mishrif四個不同層位巖心進(jìn)行了測試,并與低滲砂巖巖心數(shù)據(jù)進(jìn)行了對比。同時,利用全直徑巖心的CT掃描技術(shù)與核磁共振技術(shù)的結(jié)合,對不同孔隙發(fā)育類型的巖心進(jìn)行了孔洞縫的特征分析,研究結(jié)果表明：(1)對于低滲透碳酸鹽巖儲層,喉道半徑、孔喉半徑比是決定儲層物性的關(guān)鍵因素,在同滲透率等級下,低滲碳酸鹽巖巖芯中大部分的喉道半徑要比低滲砂巖巖芯要小,孔道半徑整體大于砂巖巖心。不同滲透率級別的低滲碳酸鹽巖巖芯,孔道半徑的峰值變化不大,但是展布范圍差別明顯,喉道半徑分布差異顯著,平均喉道半徑、平均孔喉比與滲透率呈良好的冪函數(shù)關(guān)系。(2)核磁共振測試結(jié)果表明：低滲碳酸鹽巖儲層T2譜呈現(xiàn)出單峰、雙峰和多峰的結(jié)構(gòu),T2弛豫時間的最大值高于同滲透率級別的砂巖。隨著滲透率的增加,可動流體百分?jǐn)?shù)、可動流體孔隙度增大,相關(guān)性變好,滲透率越低,非均質(zhì)性越強(qiáng)。(3)將全直徑巖心CT掃描與核磁共振技術(shù)結(jié)合,建立了針對裂縫型、孔洞型、孔隙型三種孔隙類型的識別方法,提高了針對低滲碳酸鹽巖儲層孔隙結(jié)構(gòu)分析的精確性。其中裂縫型儲層的核磁共振T2弛豫時間主要分布在10～1000ms,孔洞型儲層的核磁共振T2弛豫時間主要分布在1-1000ms,孔隙型儲層的核磁共振T2弛豫時間主要分布在1-100ms。(4)通過水測啟動壓力梯度測試,對于同一滲透率級別的巖樣進(jìn)行對比。隨著樣品滲透率增大,水測啟動壓力梯度逐漸減小,且降低幅度逐漸減弱。水測真實(shí)啟動壓力梯度和水測擬啟動壓力梯度與滲透率均存在很好的冪函數(shù)關(guān)系,是儲層綜合評價的一個重要參數(shù)。(5)在油水相對滲透率測試實(shí)驗(yàn)中,通過考慮油、水粘度以及水相的有效滲透率,分別計(jì)算得到了不同儲層不同滲透率級別的油、水相最大流度,通過該流度反映并對比了不同儲層間油水兩相流動難易程度。(6)根據(jù)研究的A油田低滲碳酸鹽巖儲層特性,結(jié)合傳統(tǒng)的孔滲油藏分類方法,提出了低滲碳酸鹽巖油藏四元分綜合分類系數(shù),對中東A油田的低滲碳酸鹽巖不同儲層進(jìn)行分類評價,評價結(jié)果為Mishrif為Ⅰ類、Sadi和Tanuma為Ⅱ類、Khasib為Ⅲ類。
[Abstract]:Low permeability carbonate reservoir is an important reservoir type in overseas oil and gas development in our country. The micro pore throat structure of this reservoir is complex, and it is obviously different from low permeability sandstone reservoir. There is an urgent need for research on reservoir evaluation of low permeability carbonate reservoirs. Due to the complex development of pore fractures in low permeability carbonate reservoirs, it is difficult to evaluate them accurately by conventional reservoir evaluation methods. In this paper, four layers of cores, Sadiang Tanuma, Khasib and Mishrif, are tested by means of constant velocity mercury injection experiment, nuclear magnetic resonance test, starting pressure gradient test and oil-water two-phase percolation rule experiment, and are compared with the low-permeability sandstone core data. At the same time, with the combination of CT scanning and nuclear magnetic resonance (NMR) technology of full-diameter cores, the characteristics of pore fractures in cores with different pore development types are analyzed. The results show that the throat radius of low permeability carbonate reservoirs is determined by the study. The pore throat radius ratio is the key factor to determine the reservoir physical properties. Under the same permeability level, the throat radius of most of the low permeability carbonate core is smaller than that of the low permeability sandstone core, and the overall pore radius is larger than the sandstone core. In low permeability carbonate cores with different permeability levels, the peak value of pore radius does not change much, but the distribution of throat radius is obviously different, and the average throat radius is different. The results of nuclear magnetic resonance (NMR) showed that the T2 spectrum of low permeability carbonate reservoir showed a single peak, two peaks and multiple peaks, and the maximum value of T2 relaxation time was higher than that of sandstone of the same permeability level. With the increase of permeability, the percentage of movable fluid and the porosity of movable fluid increase, and the correlation becomes better. The lower the permeability, the stronger the heterogeneity. The accuracy of pore structure analysis for low permeability carbonate reservoir is improved by identifying three pore types. Among them, the NMR T2 relaxation time of fractured reservoir is mainly distributed in 10 ~ 1000ms, that of porosity reservoir is mainly distributed between 1-1000ms, and that of porous reservoir is mainly distributed between 1-100ms.Ni4) Dynamic pressure gradient test, The rock samples of the same permeability level are compared. With the increase of sample permeability, the starting pressure gradient of water measurement decreases gradually, and the decreasing amplitude decreases gradually. There is a good power function relationship between real start-up pressure gradient and pseudo-start-up pressure gradient and permeability, which is an important parameter in reservoir comprehensive evaluation. The water viscosity and the effective permeability of the water phase are calculated respectively to obtain the oil with different permeability levels in different reservoirs and the maximum mobility of the water phase. The mobility reflects and contrasts the difficulty degree of oil-water two-phase flow between different reservoirs. According to the characteristics of low-permeability carbonate reservoir in A oilfield studied, combined with the traditional classification method of pore and permeability reservoir, This paper presents a comprehensive classification coefficient of four elements for low permeability carbonate reservoir, and evaluates the different reservoirs of low permeability carbonate rock in Middle East A oilfield. The results show that Mishrif is class 鈪，

本文編號：1802733