CAJ | 학술논문

鄂尔多斯盆地长7致密油储层致密、油藏低压。储层天然微裂缝发育程度和岩石脆性评价表明，盆地致密油储层物性对水平井分段体积压裂具有良好的适应性。以提高水平井多段压裂井网形式和布缝的匹配性为目的，优化了与注采井网相适配的施工参数，结果表明，实现体积压裂的排量为4~8 m3/min，单段砂量40~80 m3，入地液量300~700 m3，并形成了“低黏液体造缝、高黏液体携砂、组合粒径支撑剂、不同排量注入”的混合压裂设计模式。矿场井下微地震监测对比了体积压裂与常规压裂对裂缝扩展形态的影响，结果显示致密储层采用体积压裂的改造体积和复杂指数是常规压裂的2倍左右，且与井网适配性良好。通过开展致密油开发矿场先导性试验，水平井单井初期产量达到8~10 t/d，第1年累计产油量达2000 t左右，且无裂缝性见水井，证明对于鄂尔多斯盆地的致密油开发，采用水平井五点井网+混合水体积压裂可以获得较高的单井产量和良好的开发效益。该项技术对其他油田的非常规储层开发有一定的借鉴意义。
악이다사분지장7치밀유저층치밀、유장저압。저층천연미렬봉발육정도화암석취성평개표명，분지치밀유저층물성대수평정분단체적압렬구유량호적괄응성。이제고수평정다단압렬정망형식화포봉적필배성위목적，우화료여주채정망상괄배적시공삼수，결과표명，실현체적압렬적배량위4~8 m3/min，단단사량40~80 m3，입지액량300~700 m3，병형성료“저점액체조봉、고점액체휴사、조합립경지탱제、불동배량주입”적혼합압렬설계모식。광장정하미지진감측대비료체적압렬여상규압렬대렬봉확전형태적영향，결과현시치밀저층채용체적압렬적개조체적화복잡지수시상규압렬적2배좌우，차여정망괄배성량호。통과개전치밀유개발광장선도성시험，수평정단정초기산량체도8~10 t/d，제1년루계산유량체2000 t좌우，차무렬봉성견수정，증명대우악이다사분지적치밀유개발，채용수평정오점정망+혼합수체적압렬가이획득교고적단정산량화량호적개발효익。해항기술대기타유전적비상규저층개발유일정적차감의의。
Chang 7 tight oil reservoir of Ordos Basin features tight and low-pressure reservoir. It is shown from natural microfracture development degree and rock brittleness assessment of the reservoir that, properties of tight oil reservoir of the basin are highly adaptable to segmented volume fracturing of horizontal wells. The construction parameters which match with lfood pattern are optimized for the purpose of improving compatibility between multi-segment fracturing pattern form and fracture distribution of horizontal wells, and results indicate that volume fracturing is realized by displacement between 4 m3/min to 8m3/min, single-segment sand amount between 40 m3 to 80 m3, and buried liquid amount between 300 m3 to 700 m3. The mixed fracturing design mode of fracture formation by low-viscosity liquid, sand carrying by high-viscosity liquid, propping agent with combined grain sizes, and injection with different displacements is formed. Inlfuence on fracture spreading form by volume fracturing is compared with that on fracture spreading form by conventional fracturing in underground micro-seismic monitoring in mine ifeld, and results show that transformation volume and complexity indicator for tight oil reservoir by volume fracturing are about 2 times of those for tight oil reservoir by conventional fracturing, and the data match with well pattern properly. It can be seen from pilot test for tight oil exploitation in mine ifeld that initial output of a single horizontal well reaches 8 t/d to 10 t/d, accumulative oil production reaches about 2 000 t in the ifrst year, and there is no breakthrough well with fracture It proves that for tight oil exploitation of Ordos Basin, the technology of ifve-point pattern with mixed water volume fracturing for horizontal wells can realize high single-well output and favorable exploitation beneifts. Therefore, the technology is of certain signiifcance for reference for exploitation of unconventional reservoirs of other oilifelds.