【摘要】：斷層穩(wěn)定性是指先存斷層在應(yīng)力場(chǎng)條件下發(fā)生再活動(dòng)的風(fēng)險(xiǎn)程度,油田范圍內(nèi)斷層再活動(dòng)主要源于斷層帶內(nèi)流體壓力的增加。其定量評(píng)價(jià)指標(biāo)為當(dāng)前孔隙流體壓力條件下斷層再活動(dòng)所需臨界流體壓力(即附加流體壓力),地層孔隙壓力達(dá)到臨界壓力時(shí),相應(yīng)的斷層部位將處于臨界應(yīng)力狀態(tài),臨界應(yīng)力斷層發(fā)生滑動(dòng)容易造成油氣的滲漏以及斷層邊部井眼套損等問(wèn)題,因此研究斷層穩(wěn)定性對(duì)油田生產(chǎn)具有極其重要的意義。地應(yīng)力是斷層穩(wěn)定性評(píng)價(jià)的關(guān)鍵參數(shù),地應(yīng)力場(chǎng)獲取有多種方法,包括水力學(xué)方法、聲發(fā)射法以及測(cè)井資料計(jì)算地應(yīng)力等,其中水力壓裂法能夠獲得精確的水平最小主應(yīng)力的大小,本文利用測(cè)井資料進(jìn)行計(jì)算獲得了連續(xù)的地應(yīng)力剖面。斷層穩(wěn)定性評(píng)價(jià)有多種方法,其中FAST(斷層封閉性分析技術(shù))方法應(yīng)用較為廣泛,該方法不僅可以對(duì)斷層穩(wěn)定性進(jìn)行定量評(píng)價(jià),而且兼顧了斷層內(nèi)聚力對(duì)斷層穩(wěn)定性的作用。影響斷層穩(wěn)定性的因素有很多,差應(yīng)力和斷層巖抗張強(qiáng)度的相互關(guān)系會(huì)影響斷層再活動(dòng)的趨勢(shì)類型,應(yīng)力場(chǎng)方向?qū)鄬臃�(wěn)定性也有很大的影響;泥質(zhì)成分對(duì)斷層巖強(qiáng)度具有弱化作用,有大量泥質(zhì)卷入的斷裂帶易于再活動(dòng);儲(chǔ)層流體壓力的變化也會(huì)導(dǎo)致水平應(yīng)力的變化從而對(duì)斷層穩(wěn)定性造成影響;此外地震解釋精度也會(huì)影響斷層穩(wěn)定性的評(píng)價(jià)結(jié)果。本文基于穩(wěn)定性機(jī)理及斷層穩(wěn)定性影響因素分析,在獲得地應(yīng)力、流體壓力以及斷層力學(xué)性質(zhì)資料的基礎(chǔ)之上對(duì)渤中34-2/4油田2區(qū)Ⅱ、Ⅲ和Ⅳ油組斷層穩(wěn)定性進(jìn)行了定量評(píng)價(jià)。渤中34-2/4油田現(xiàn)今應(yīng)力場(chǎng)環(huán)境下沙河街組最優(yōu)向斷層產(chǎn)狀為160°∠61.5°和340°∠61.5°,隨著地層流體壓力持續(xù)增加接近該產(chǎn)狀的斷層部位首先達(dá)到臨界應(yīng)力狀態(tài)。渤中34-2/4油田2區(qū)北中塊Ⅱ、Ⅲ和Ⅳ油組斷層穩(wěn)定性評(píng)價(jià)結(jié)果顯示,Ⅱ油組主要斷層不發(fā)生再活動(dòng)所允許的附加流體壓力范圍為6.1-29.8 MPa,Ⅲ油組主要斷層不發(fā)生再活動(dòng)所允許的附加流體壓力范圍為6.4-29.8 MPa,Ⅳ油組主要斷層不發(fā)生再活動(dòng)所允許的附加流體壓力范圍為6.6-29.7 MPa。斷層風(fēng)險(xiǎn)性最大的部位為F30斷層上BZ34-2-1井西側(cè)部位以及F31斷層北東向末端,現(xiàn)今孔隙壓力條件下所能承受的最大流體增壓分別為6.5 MPa和6.1 MPa。
[Abstract]:The fault stability refers to the degree of risk that the pre-existing fault occurs under the stress field, and the fault re-activity in the field is mainly due to the increase of the fluid pressure in the fault zone. The quantitative evaluation index is the critical fluid pressure (i.e., the additional fluid pressure) required for the fault re-activity under the current pore fluid pressure condition, and when the formation pore pressure reaches the critical pressure, the corresponding fault part will be in the critical stress state, It is of great significance to study the stability of the fault to the production of the oil field. The ground stress is the key parameter of the fault stability evaluation, and the ground stress field is obtained with a variety of methods, including the hydraulic method, the acoustic emission method and the well logging data to calculate the ground stress, etc., in which the hydraulic fracturing method can obtain the accurate horizontal minimum principal stress, In this paper, the continuous ground stress profile is obtained by using logging data. The fault stability evaluation has a variety of methods, in which the method of the FAST (fault sealing analysis technique) is widely used. The method not only can quantitatively evaluate the fault stability, but also takes into account the effect of the fault cohesion on the fault stability. There are many factors that affect the stability of the fault, and the relationship between the difference stress and the tensile strength of the fault rock can influence the trend type of the fault re-activity, and the stress field direction has a great influence on the fault stability; the argillaceous component has a weakening effect on the strength of the fault rock, The fault zone with a large amount of argillaceous involvement is prone to reactivity; the change of the reservoir fluid pressure can also lead to a change in the horizontal stress, which can affect the stability of the fault; moreover, the accuracy of the seismic interpretation can also influence the evaluation result of the fault stability. Based on the analysis of the stability mechanism and the influence factors of the fault stability, the fault stability of the two zones 鈪，

本文編號(hào)：2499640