【摘要】：受頁巖儲層低滲透物性的影響,頁巖氣(油)藏需要經(jīng)過水力壓裂改造后才能開采。由于水平井在增加與儲層接觸面積、降低費用、擁有長期的穩(wěn)產(chǎn)能力等方面具有明顯的優(yōu)勢,它在頁巖氣開發(fā)中得到了廣泛的應(yīng)用,尤其是與滑溜水多級壓裂相配合時,增產(chǎn)效果更為顯著。絕大多數(shù)壓裂作業(yè)是在套管射孔完井之后進行的,而水力裂縫的起裂與頁巖巖石力學特性和頁巖儲層力學性質(zhì)的非均勻性息息相關(guān),因而射孔完井后實際的裂縫起裂和延伸是復雜多樣的。此外,頁巖儲層常發(fā)育有大量天然裂縫和層理,對頁巖儲層的水力壓裂可形成大規(guī)模網(wǎng)狀裂縫,這就是通常的體積壓裂的效果。本文在中國石油科技創(chuàng)新基金資助項目(2013D-5006-0211)、國家自然科學基金資助項目(51479024)、國家重點基礎(chǔ)研究計劃973項目(2014CB047103)的資助下,基于對前人闡述的巖體水力壓裂機理的認識,從壓裂過程中水力耦合作用的滲流-應(yīng)力-損傷模型出發(fā),并使其在有限元軟件RFPA滲流版中實現(xiàn),對有限的巖心物理實驗結(jié)果進行了模擬和分析評價,得到后續(xù)有關(guān)章節(jié)相關(guān)的實驗參數(shù),進而開展對頁巖儲層水平井水力裂縫的起裂和擴展特征的數(shù)值模擬研究。首先,對水平井定向射孔水力裂縫的起裂特征進行了數(shù)值模擬研究,并就地應(yīng)力差和射孔方位角兩因素對其影響建立數(shù)值模型展開了詳細分析,得到的結(jié)果顯示有水力裂縫可能不在射孔端起裂的情況,在此基礎(chǔ)上,進一步探討了壓裂雙裂縫形成的可能性和條件。此外,模擬了裂縫延伸至產(chǎn)層與隔層界面處的穿層現(xiàn)象。數(shù)值分析結(jié)果進一步豐富對水平井射孔參數(shù)優(yōu)化及水力壓裂施工的研究。其次,鑒于頁巖儲層通常發(fā)育有大量的天然裂縫,對層狀頁巖儲層中水力裂縫與天然層理的相互作用以及縫網(wǎng)的形成規(guī)律進行了數(shù)值模擬,借鑒水平應(yīng)力差異系數(shù)初步分析體積壓裂技術(shù)的效果,同時建立數(shù)值模型分析了地應(yīng)力差、脆性指數(shù)、層理特征等因素對形成的壓裂縫網(wǎng)復雜程度的影響,希望能對頁巖儲層壓裂縫網(wǎng)形成的研究和設(shè)計提供些許參考。最后,依據(jù)目標儲層實際情況對單井不同間距裂縫周圍的應(yīng)力分布及相互干擾現(xiàn)象進行了數(shù)值分析,對壓裂裂縫間距進行優(yōu)化選擇,并進一步分析了兩井同步壓裂時壓裂段裂縫的合理間距,在此基礎(chǔ)上,綜合評價了兩種壓裂方案。
[Abstract]:Affected by the low permeability of shale reservoir, shale gas (oil) reservoir needs hydraulic fracturing before it can be exploited. Because horizontal well has obvious advantages in increasing contact area with reservoir, reducing cost and having long-term stable production ability, it has been widely used in shale gas development, especially when cooperating with slippery water multistage fracturing. The effect of increasing production is more remarkable. Most fracturing operations take place after casing perforation, and the initiation of hydraulic fractures is closely related to the mechanical properties of shale rocks and the nonuniformity of shale reservoir mechanical properties. Therefore, the actual fracture initiation and extension after perforation completion is complex and diverse. In addition, a large number of natural fractures and bedding are often developed in shale reservoirs. Hydraulic fracturing of shale reservoirs can form large scale network fractures, which is the effect of normal volume fracturing. This paper is supported by the China Petroleum Science and Technology Innovation Fund (2013D-5006-0211), the National Natural Science Foundation of China (51479024) and the State key basic Research Program 973 (2014CB047103). Based on the understanding of hydraulic fracturing mechanism of rock mass described by predecessors, the seepage stress-damage model of hydraulic coupling action in fracturing process is set out, and it is realized in the finite element software RFPA percolation plate. The finite core physical experimental results are simulated and evaluated, and the experimental parameters related to the subsequent chapters are obtained, and the numerical simulation of the fracture initiation and propagation characteristics of horizontal well in shale reservoir is carried out. Firstly, numerical simulation of the initiation characteristics of directional perforating hydraulic fractures in horizontal wells is carried out, and a numerical model is established to analyze the effects of two factors: ground stress difference and perforation azimuth. The results show that hydraulic fractures may not occur at the perforation end. On this basis, the possibility and conditions of the formation of fracturing double fractures are further discussed. In addition, the phenomenon of the fracture extending to the interface between the production layer and the interlayer is simulated. The numerical analysis results further enrich the research on the optimization of perforation parameters and hydraulic fracturing operation of horizontal wells. Secondly, in view of the large number of natural fractures in shale reservoirs, the interaction between hydraulic fractures and natural beddings in layered shale reservoirs and the formation of fracture networks are numerically simulated. Using horizontal stress difference coefficient for reference, the effect of volume fracturing technique is preliminarily analyzed. At the same time, a numerical model is established to analyze the influence of factors such as ground stress difference, brittleness index and bedding characteristics on the complex degree of fracture network formed. It is hoped that this paper can provide some references for the research and design of the formation of fracture network in shale reservoir. Finally, according to the actual situation of the target reservoir, the stress distribution and interferences around the fractures with different spacing in single well are analyzed numerically, and the fracture spacing is optimized. On the basis of the analysis of the reasonable fracture spacing between the two wells during synchronous fracturing, two fracturing schemes are comprehensively evaluated.
【學位授予單位】：大連理工大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TE357.1

【參考文獻】

相關(guān)期刊論文 前6條

1 陳遠林;郭建春;魏星;鐘飛翔;劉正云;;清水壓裂技術(shù)增注機理及現(xiàn)場應(yīng)用[J];斷塊油氣田;2008年02期

2 王治中;鄧金根;趙振峰;慕立俊;劉建安;田紅;;井下微地震裂縫監(jiān)測設(shè)計及壓裂效果評價[J];大慶石油地質(zhì)與開發(fā);2006年06期

3 劉建中;劉翔鶚;孫聚晨;余建華;徐昆;;水平井水力壓裂真三維物理模擬實驗[J];石油勘探與開發(fā);1993年06期

4 陳勉;周健;金衍;張廣清;;隨機裂縫性儲層壓裂特征實驗研究[J];石油學報;2008年03期

5 楊宇,孫致學,郭春華;用灰色模型預(yù)測水力壓裂縫導流能力[J];石油與天然氣地質(zhì);2004年01期

6 朱海燕;鄧金根;劉書杰;閆偉;陳崢嶸;文敏;彭成勇;;定向射孔水力壓裂起裂壓力的預(yù)測模型[J];石油學報;2013年03期

相關(guān)博士學位論文 前1條

1 杜春志;煤層水壓致裂理論及應(yīng)用研究[D];中國礦業(yè)大學;2008年

，

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