本文選題：水平裂縫 + 產(chǎn)能計算��； 參考：《西南石油大學(xué)》2015年碩士論文

【摘要】：特低滲砂巖油藏開發(fā)通常進(jìn)行水力壓裂,淺層儲層壓裂形成的裂縫以水平縫為主,且該類儲層本身含有天然微裂縫,如我國大慶油田、延長油田、吉林油田等。在開發(fā)過程中隨著地層壓力下降,基質(zhì)滲透率與裂縫導(dǎo)流能力均降低,油井生產(chǎn)指標(biāo)與不考慮應(yīng)力敏感時有較大差別,如產(chǎn)能、采出程度、地層壓力等。此外,應(yīng)力敏感實驗測試方法和評價方法有待改進(jìn),考慮應(yīng)力敏感的壓裂水平縫油藏產(chǎn)能計算方法需進(jìn)一步研究。 本文首先對應(yīng)力敏感進(jìn)行理論研究,確定巖石孔隙壓縮系數(shù)和巖石滲透率有效應(yīng)力系數(shù)；在理論研究的基礎(chǔ)上對實驗方法和評價方法進(jìn)行改進(jìn),進(jìn)行了天然巖心、人造裂縫巖心應(yīng)力敏感實驗測試及影響因素分析；最后將實驗得到的應(yīng)力敏感模型應(yīng)用到油藏工程和數(shù)值模擬中,建立考慮應(yīng)力敏感的壓裂水平縫直井產(chǎn)能計算方法,分析了應(yīng)力敏感和水平縫參數(shù)對壓裂直井產(chǎn)能及其他開發(fā)指標(biāo)的影響。 本文取得的主要研究成果如下： (1)推導(dǎo)出了巖石孔隙壓縮系數(shù)表達(dá)式,巖石孔隙壓縮系數(shù)與有效應(yīng)力系數(shù)相關(guān),隨著孔隙度的減小巖石孔隙壓縮系數(shù)降低。 (2)給出了一種簡單的有效應(yīng)力系數(shù)理論計算公式及一種簡單的實驗測定方法,有效應(yīng)力系數(shù)的大小與巖石的孔隙度和泊松比有關(guān),利用孔隙度和巖石泊松比可直接計算出巖石的有效應(yīng)力系數(shù)。 (3)應(yīng)力敏感實驗測試優(yōu)選采用有效應(yīng)力系數(shù)修正的定內(nèi)壓變圍壓方法,可準(zhǔn)確評價儲層應(yīng)力敏感性,該方法同時可將實際油藏高壓條件轉(zhuǎn)化為實驗室低壓條件進(jìn)行。 (4)以儲層原始有效應(yīng)力為起點,特低滲砂巖基質(zhì)應(yīng)力敏感程度為中等偏弱。人造裂縫未填充時隨著圍壓的增加滲透率急劇下降,卸載圍壓后滲透率恢復(fù)程度很低,應(yīng)力敏感性中等偏強；裂縫填充后應(yīng)力敏感性相對變?nèi)?圍壓卸載后滲透率恢復(fù)程度變高,應(yīng)力敏感性為中等。 (5)溫度從30℃增加到150℃巖石滲透率損害增加了3.8%,應(yīng)力敏感強度隨著溫度的升高略增大。此外,滑脫效應(yīng)、時效性、驅(qū)替壓產(chǎn)等對應(yīng)力敏感實驗測試存在影響。 (6)推導(dǎo)出了考慮應(yīng)力敏感的壓裂水平縫直井產(chǎn)能計算公式,該公式可應(yīng)用于X油田產(chǎn)能計算,相對于現(xiàn)有的壓裂水平縫直井產(chǎn)能計算方法誤差更小。 (7)以X油田為例通過數(shù)值模擬分析得出：合理穿透比為0.5左右；水平縫臨界導(dǎo)流能力為15D·cm左右；壓裂水平縫間距為4m條比較合理；水平縫形狀對產(chǎn)能影響不大；水平縫對稱性對初期產(chǎn)量影響較大,對中后期影響很小。同時得出：只考慮滲透率應(yīng)力敏感后單井日產(chǎn)量降低、采出程度降低、穩(wěn)產(chǎn)期下降。
[Abstract]:In the development of ultra-low permeability sandstone reservoir, hydraulic fracturing is usually carried out. The fractures formed by shallow reservoir fracturing are mainly horizontal fractures, and this kind of reservoir itself contains natural micro-fractures, such as Daqing Oilfield, Yanchang Oilfield, Jilin Oilfield and so on.During the development process, with the decrease of formation pressure, the matrix permeability and fracture conductivity decrease, and the production index of oil well is different from that when stress sensitivity is not considered, such as productivity, recovery degree, formation pressure and so on.In addition, the stress sensitivity test method and evaluation method need to be improved, and the productivity calculation method of fracturing horizontal fracture reservoir considering stress sensitivity should be further studied.In this paper, the stress sensitivity is studied theoretically to determine the pore compressibility coefficient and the effective stress coefficient of rock permeability, and the experimental method and evaluation method are improved on the basis of the theoretical study, and the natural core is carried out.The stress sensitivity test of artificial fracture core and the analysis of the influencing factors are carried out. Finally, the stress-sensitive model is applied to reservoir engineering and numerical simulation, and the productivity calculation method of horizontal fractured straight well considering stress sensitivity is established.The effects of stress sensitivity and horizontal fracture parameters on productivity and other development indexes of fracturing vertical wells are analyzed.The main research results obtained in this paper are as follows:The pore compressibility coefficient of rock is related to the effective stress coefficient and decreases with the decrease of porosity.A simple formula for calculating effective stress coefficient and a simple experimental method are given. The magnitude of effective stress coefficient is related to porosity and Poisson's ratio of rock.The effective stress coefficient of rock can be calculated directly by using porosity and Poisson's ratio.3) the stress sensitivity test can be used to evaluate the reservoir stress sensitivity by using the effective stress coefficient modified local pressure variation method. The method can transform the actual reservoir high pressure condition into the laboratory low pressure condition at the same time.(4) taking the original effective stress of reservoir as the starting point, the stress sensitivity of the matrix of ultra-low permeability sandstone is moderate and weak.The permeability of artificial fracture decreases sharply with the increase of confining pressure, the recovery degree of permeability after unloading confining pressure is very low, the stress sensitivity is relatively strong, and the stress sensitivity is relatively weak after fracture filling.The permeability recovery degree becomes higher and the stress sensitivity is medium after confining pressure unloading.The permeability damage of rock increased from 30 鈩，

本文編號：1768298