本文選題：致密儲(chǔ)層 + 凝析氣藏��； 參考：《西南石油大學(xué)》2015年博士論文

【摘要】：致密砂巖凝析氣藏作為非常規(guī)油氣藏的重要組成部分,在我國(guó)油氣資源儲(chǔ)量及產(chǎn)量構(gòu)成中占有重要地位,相關(guān)研究也已經(jīng)受到重視。由凝析氣藏特殊的相態(tài)變化特征可知在衰竭開采過(guò)程中,地層壓力下降會(huì)導(dǎo)致凝析油析出并吸附滯留在儲(chǔ)層孔隙孔道中,將對(duì)儲(chǔ)層滲透性造成不同程度的傷害。致密砂巖凝析氣藏儲(chǔ)層非均質(zhì)性強(qiáng)、孔隙度和滲透率低、表面大、毛管壓力高,其儲(chǔ)層滲透性更易受到反凝析傷害的影響。然而目前針對(duì)致密砂巖凝析氣藏研究的文獻(xiàn)報(bào)道還較少,在反凝析傷害機(jī)理及合理開發(fā)方式等方面存在認(rèn)識(shí)空白,是此類氣藏高效開發(fā)亟待解決的問(wèn)題。為此,本文依托致密砂巖全直徑巖心,首先在常溫低壓條件下完成了15組實(shí)驗(yàn),測(cè)試了不同初始含水飽和度條件下的水驅(qū)氣相滲及啟動(dòng)壓力梯度,探討了水鎖傷害程度與規(guī)律；接著在高溫高壓條件下進(jìn)行了7組反凝析傷害評(píng)價(jià)實(shí)驗(yàn),考慮了不同凝析油含量、不同反凝析區(qū)域及不同儲(chǔ)層類型等因素,通過(guò)對(duì)比分析各組反凝析傷害實(shí)驗(yàn)結(jié)果的差異,揭示了反凝析傷害機(jī)理；然后在高溫高壓條件下開展了針對(duì)中、高含凝析油的孔隙型及裂縫-孔隙型致密砂巖凝析氣藏在衰竭開發(fā)、循環(huán)注氣、吞吐注氣、脈沖注氣等方式下的開采動(dòng)態(tài)物理模擬實(shí)驗(yàn)18組,以最大限度地獲得凝析油采收率為目的并結(jié)合礦場(chǎng)實(shí)際優(yōu)選了合理的開發(fā)方式；最后推導(dǎo)了考慮應(yīng)力敏感的裂縫-孔隙型凝析氣藏物質(zhì)平衡方程。通過(guò)上述研究取得了一系列對(duì)生產(chǎn)實(shí)際具有重要指導(dǎo)意義的成果和認(rèn)識(shí),主要包括：(1)致密砂巖氣藏初始含水飽和度對(duì)氣相滲透率及啟動(dòng)壓力梯度均有較大影響。隨著初始含水飽和度增加,氣相有效滲透率逐漸降低,啟動(dòng)壓力梯度逐漸增大；相同初始含水飽和度條件下,隨巖石物性變差,啟動(dòng)壓力梯度變大。(2)致密砂巖凝析氣藏衰竭開發(fā)過(guò)程中遠(yuǎn)井區(qū)和近井區(qū)反凝析傷害程度及差異程度主要受凝析油含量影響。對(duì)于相同區(qū)域而言,凝析油含量越高,發(fā)生反凝析傷害的壓力越高,傷害程度更嚴(yán)重。對(duì)不同區(qū)域而言,當(dāng)凝析油含量較低時(shí),近井區(qū)反凝析傷害程度大于遠(yuǎn)井區(qū),隨著地層壓力降低,傷害程度越嚴(yán)重且兩個(gè)區(qū)域差異越大。當(dāng)凝析油含量較高時(shí),由于凝析油析出量大,達(dá)到其臨界流動(dòng)飽和度,遠(yuǎn)井區(qū)與近井區(qū)傷害程度基本一致。(3)裂縫發(fā)育的致密砂巖儲(chǔ)層,相比基質(zhì),流體在裂縫中更易流動(dòng),凝析油臨界流動(dòng)飽和度更低,氣液兩相流動(dòng)導(dǎo)致氣相滲透率大幅度降低。裂縫儲(chǔ)層反凝析傷害程度比孔隙型儲(chǔ)層更嚴(yán)重。壓裂可以提高氣相滲流能力,但不能降低反凝析傷害程度。(4)對(duì)于裂縫欠發(fā)育的致密砂巖凝析氣藏,衰竭式開采凝析油采收率低,衰竭速度、初始含水飽和度對(duì)開發(fā)效果影響不大；凝析油含量高的氣藏凝析油可流動(dòng),凝析油采收率略高；注氣可大幅度提高凝析油采收率。(5)裂縫發(fā)育的致密砂巖凝析氣藏,裂縫與基巖的滲透率級(jí)差大,基巖供給不足,衰竭開采凝析油采收率低,注氣開發(fā)時(shí)氣竄快,循環(huán)注氣和吞吐注氣效果不理想。(6)考慮現(xiàn)場(chǎng)實(shí)際可操作性及工藝要求,針對(duì)裂縫欠發(fā)育的致密砂巖氣藏可考慮前期衰竭開采、后期吞吐注氣開發(fā),裂縫發(fā)育的致密砂巖凝析氣藏建議采用前期衰竭式開采、后期脈沖注氣開發(fā)。
[Abstract]:As an important component of unconventional oil and gas reservoirs, tight sandstone condensate reservoir plays an important role in the reserves and yield components of oil and gas in China, and the related research has been paid attention to. The special phase change characteristics of condensate gas reservoir can be seen that the decline of formation pressure will lead to the precipitation and retention of condensate oil in the process of depletion mining. In the pore pore channel, the reservoir permeability will be injured in different degrees. The tight sandstone condensate gas reservoir has strong heterogeneity, low porosity and permeability, large surface and high capillary pressure, and the permeability of the reservoir is more vulnerable to the effect of reverse condensate damage. However, there are few literature reports on the study of condensate gas reservoir in tight sandstone. In this paper, we have completed 15 groups of experiments under the condition of normal temperature and low pressure, and tested the water flooding and starting pressure of water flooding under the conditions of different initial water saturation. Gradient, the degree and law of water lock damage are discussed, and 7 groups of anti condensate damage evaluation experiments are carried out under high temperature and high pressure. The factors of different condensate oil content, different reverse condensate region and different reservoir types are considered. By comparing and analyzing the differences of the experimental results of each group of reverse condensate damage, the mechanism of reverse condensate injury is revealed. Under the conditions of high temperature and high pressure, 18 groups of dynamic physical simulation experiments are carried out in the pore type and fractured pore type tight sandstone condensate gas reservoir with high concentration of condensate in failure development, circulation gas injection, gas injection and pulse gas injection, in order to maximize the recovery of condensate oil recovery and to optimize the actual optimization of the field. In the end, a series of important guiding significance for the production practice and understanding are obtained through the above study, which mainly include: (1) the initial water saturation of the tight sandstone gas reservoir to the gas phase permeability and the starting pressure ladder. With the increase of initial water saturation, the effective permeability of gas phase decreases gradually and the starting pressure gradient increases gradually. Under the same initial water saturation conditions, the starting pressure gradient becomes larger with the variation of rock physical property. (2) the extent of reverse Condensate Damage in the far and near well areas of the tight sandstone condensate reservoir failure process. The higher the condensate oil content, the higher the condensate oil content, the higher the pressure of the reverse Condensate Damage and the more serious damage. For different regions, when the content of condensate oil is low, the damage degree of the reverse condensate in the near well area is greater than that in the far well area, and the damage degree is more serious as the formation pressure decreases. The greater the difference between the two regions. When the condensate content is high, the amount of condensate oil is large and its critical flow saturation is reached. The damage degree of the far well area and the near well area is basically the same. (3) the tight sandstone reservoir developed by the fracture is more easy to flow in the crack than the matrix, and the critical flow saturation of the condensate oil is lower, and the gas liquid two phase flow guide is guided. The permeability of gas phase is greatly reduced. The degree of reverse Condensate Damage in fractured reservoir is more serious than that of pore type reservoir. Fracturing can improve the capacity of gas phase seepage, but it can not reduce the degree of reverse condensate damage. (4) for the tight sandstone condensate reservoir under the undeveloped fracture, the failure mode mining condensate oil recovery rate is low, the failure velocity and initial water saturation are open. There is little effect on the effect; the condensate oil with high condensate oil content can flow, the recovery rate of condensate oil is slightly higher, and gas injection can greatly increase the recovery of condensate oil recovery. (5) the tight sandstone condensate gas reservoir with crack development, the permeability difference of the fracture and base rock is large, the bedrock supply is insufficient, the oil recovery recovery is low and the gas injection development is fast in the gas injection development. The effect of circulation gas injection and injection gas injection is not ideal. (6) considering the actual workability and technological requirements of the field, the tight sandstone gas reservoirs with less developed fractures can consider the early failure mining, the late stimulation and puff gas injection development, and the tight sandstone condensate gas reservoirs developed in the fracture development should be exploited in the early stage of depletion type mining and later pulse gas injection development.
【學(xué)位授予單位】：西南石油大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2015
【分類號(hào)】：TE372
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本文編號(hào)：2087733