馬杰 李宇 周思宇
摘 ?????要:油田低滲透率儲(chǔ)層在進(jìn)行鉆井、固井、增產(chǎn)措施等勘探、開(kāi)發(fā)環(huán)節(jié)中,儲(chǔ)層會(huì)與不同類(lèi)型的入井流體進(jìn)行接觸,當(dāng)入井液與儲(chǔ)層巖石配伍性不好,將會(huì)影響儲(chǔ)層產(chǎn)量。為了降低開(kāi)發(fā)過(guò)程中對(duì)X區(qū)塊儲(chǔ)層造成的損害,對(duì)其進(jìn)行了敏感性評(píng)價(jià)(包括速敏、水敏、應(yīng)力敏)實(shí)驗(yàn)。研究結(jié)果表明60-1HF井表現(xiàn)為強(qiáng)速敏、強(qiáng)水敏、中等偏強(qiáng)應(yīng)力敏;60-2HF井表現(xiàn)為中等偏強(qiáng)速敏、強(qiáng)水敏、強(qiáng)應(yīng)力敏;60-3HF井表現(xiàn)為中等偏弱速敏、中等偏強(qiáng)水敏、中等偏強(qiáng)應(yīng)力敏。綜合評(píng)價(jià)該區(qū)塊為中等速敏、強(qiáng)水敏、強(qiáng)應(yīng)力敏,該結(jié)果對(duì)X區(qū)塊的開(kāi)發(fā)有一定的指導(dǎo)意義。
關(guān) ?鍵 ?詞:儲(chǔ)層敏感性;速敏性;水敏性;應(yīng)力敏感
中圖分類(lèi)號(hào):TE122.2 ??????文獻(xiàn)標(biāo)識(shí)碼: A ??????文章編號(hào): 1671-0460(2019)02-0364-04
Abstract: In exploration and development links of low-permeability reservoirs such as drilling,cementing and stimulation measures, the oil reservoirs in the oil field will be exposed to different types of well-injected fluids. When the well-in-place fluids are poor compatibility with the reservoir rocks, they will affect the reservoir production. In order to reduce the damage to the X-block reservoir during the development process, sensitivity evaluation (including speed sensitivity, water sensitivity, and stress sensitivity) experiments were performed. The results indicated that the 60-1HF well was characterized by strong velocity sensitivity, strong water sensitivity, and medium-strong stress sensitivity; the 60-2HF well exhibited moderate-strong velocity sensitivity, strong water sensitivity and strong stress sensitivity; the 60-3HF well exhibited moderate-weak velocity sensitivity, moderate-strong water sensitivity and moderate-strong stress sensitivity. Comprehensive evaluation of the block is moderate speed-sensitive, strong water -sensitive, and strong stress-sensitive. This result has certain guiding significance for the development of the X block.
Key words: Reservoir sensitivity; Speed sensitivity; Water sensitivity; Stress sensitivity
儲(chǔ)層損害在整個(gè)油氣勘探開(kāi)發(fā)中都是油藏工程師的首要問(wèn)題,油田采取的增產(chǎn)措施均可能造成油氣儲(chǔ)層的傷害,只有通過(guò)了解儲(chǔ)層敏感性并認(rèn)識(shí)其產(chǎn)生的機(jī)理才能根本的解決該問(wèn)題。地層損害評(píng)價(jià)以及儲(chǔ)層保護(hù)的主要內(nèi)容就是儲(chǔ)層敏感性評(píng)價(jià)與其機(jī)理的研究, 并且又是影響低滲儲(chǔ)層合理開(kāi)發(fā)的決定性因素[1]。許多學(xué)者調(diào)研了各種地區(qū)以及各種油藏類(lèi)型的儲(chǔ)層,針對(duì)低滲儲(chǔ)層的敏感性進(jìn)行了多組巖心流動(dòng)實(shí)驗(yàn),對(duì)其敏感性特征進(jìn)行了總結(jié)與分析[2]。在儲(chǔ)層敏感性成因機(jī)理研究方面 ,國(guó)內(nèi)外也取得了一定認(rèn)識(shí)[3]。對(duì)于敏感性評(píng)價(jià)國(guó)內(nèi)外已有較為完備的實(shí)驗(yàn)方法,我國(guó)有SY/T 5336行業(yè)標(biāo)準(zhǔn)明確規(guī)定實(shí)驗(yàn)流程。在儲(chǔ)層損害機(jī)理研究上,已有X衍射、掃描電鏡、CT掃描和恒速壓汞等微觀實(shí)驗(yàn)手段,可以對(duì)儲(chǔ)層巖石進(jìn)行全面詳細(xì)的宏觀以及微觀研究[4]。
1 ?儲(chǔ)層地質(zhì)作用
儲(chǔ)層地質(zhì)作用之一的壓實(shí)作用在X區(qū)塊中由下面幾點(diǎn)體現(xiàn):顆粒間從沉積初始的點(diǎn)接觸演變到現(xiàn)有的線接觸的接觸方式,其中也有少部分凹凸接觸;云母在顆粒指尖受到擠壓呈現(xiàn)撓曲變形;塑性巖屑擠壓變形、剛性顆粒破裂等。研究層段內(nèi)大量發(fā)育的碎屑顆粒廣泛形成裂隙,這為不穩(wěn)定碎屑顆粒后期遭受溶蝕改造提供了更多的滲流通道,使得溶蝕改造能夠進(jìn)行地更加深入[5]。
溶蝕作用主要表現(xiàn)在長(zhǎng)石的溶蝕以及巖屑的溶蝕,由于長(zhǎng)石的化學(xué)不穩(wěn)定性,使得長(zhǎng)石所經(jīng)歷的成巖改造在儲(chǔ)層成巖過(guò)程中表現(xiàn)地異常突出,主要包括溶蝕作用、碳酸鹽交代作用、鈉長(zhǎng)石化等。在酸性介質(zhì)條件下,長(zhǎng)石部分或全部被溶解,形成粒內(nèi)溶孔、網(wǎng)狀溶孔、溶蝕殘骸甚至全部溶蝕形成鑄???。
2 ?儲(chǔ)層敏感性評(píng)價(jià)試驗(yàn)
2.1 ?試驗(yàn)準(zhǔn)備