【摘要】：為提高低滲煤層瓦斯抽采效率,在分析頁巖氣"縫網(wǎng)壓裂"基礎(chǔ)上,提出了煤礦井下煤巖儲層縫網(wǎng)壓裂的技術(shù)思路。通過分析影響縫網(wǎng)形成的關(guān)鍵因素,采用Mshale模擬水力壓裂脆性指數(shù)-泊松比-單一水力裂縫體積三者關(guān)系,判斷天然裂縫發(fā)生張性斷裂和剪切斷裂的力學(xué)條件,試驗?zāi)M不同地應(yīng)力差水力裂縫特征。研究表明:在注入量一定條件下,隨著脆性指數(shù)增加,單一水力裂縫體積減小,水力裂縫數(shù)量增加;隨著主應(yīng)力差的增大,試樣破裂面表面積增加且漸為粗糙,裂縫張開度減小;水力裂縫和天然裂縫相交角越小,水力裂縫越易沿天然裂縫剪切破壞;主應(yīng)力差較小時,水力裂縫易出現(xiàn)轉(zhuǎn)向、分叉等。在鶴壁中泰礦業(yè)有限公司進行了縫網(wǎng)壓裂試驗,壓裂有效面積達21 666 m2,鉆孔日抽采量是縫網(wǎng)壓裂前的13倍,是常規(guī)水力壓裂的2.6倍,采用CYT探測了水平剖面和垂直剖面視電阻率的變化,證實了水力壓裂縫網(wǎng)的存在。
[Abstract]:In order to improve the efficiency of gas extraction in low permeability coal seam, based on the analysis of shale gas "fracture net fracturing", the technical idea of fracture net fracturing in underground coal and rock reservoir is put forward. By analyzing the key factors affecting the formation of fracture net, Mshale is used to simulate the relationship between hydraulic fracturing brittleness index, Poisson's ratio and single hydraulic fracture volume, and the mechanical conditions of tensile fracture and shear fracture of natural fracture are judged. The characteristics of hydraulic fissures with different ground stress differences are simulated. The results show that with the increase of brittleness index, the volume of single hydraulic fracture decreases and the number of hydraulic fracture increases. With the increase of principal stress difference, the surface area of the fracture surface increases and becomes rough, and the fracture opening decreases, and the smaller the intersection angle between the hydraulic fracture and the natural fracture, the easier the hydraulic fracture is to shear along the natural fracture. When the principal stress difference is small, hydraulic cracks are easy to appear steering, bifurcation and so on. The fracture net fracturing test was carried out in Hebi Zhongtai Mining Co., Ltd., the effective area of fracturing is 21 666 m 2, and the daily extraction amount of drilling is 13 times as much as that before fracture net fracturing and 2.6 times as much as that of conventional hydraulic fracturing. The apparent resistance of horizontal section and vertical section is detected by CYT, and the existence of hydraulic pressure fracture network is confirmed.
【作者單位】： 河南理工大學(xué)能源科學(xué)與工程學(xué)院;中原經(jīng)濟區(qū)煤層(頁巖)氣河南省協(xié)同創(chuàng)新中心;河南能源化工集團研究院有限公司;
【基金】：2015年河南省科技攻關(guān)資助項目(152102310095) 焦作市科技局科技攻關(guān)資助項目(應(yīng)用基礎(chǔ)研究)(2014400018)
【分類號】：TD712.6
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本文編號：2480039