W12油田群井壁穩(wěn)定及井身結構優(yōu)化研究
發(fā)布時間：2019-04-09 08:31
【摘要】：井壁穩(wěn)定問題是鉆井工程中經(jīng)常遇到的一個十分復雜的難題,W12油田群位于南海西部北部灣盆地,在近期鉆井作業(yè)中該地區(qū)常常遇到井壁失穩(wěn)而影響鉆井速度的情況,造成作業(yè)時效低,成本高,嚴重影響鉆完井勘探開發(fā)的進度,并影響最后的綜合經(jīng)濟效益。W12油田群是即將開發(fā)的新油田,計劃新建多個平臺進行開發(fā),開發(fā)幾十口井。縱觀前期鄰井的鉆井作業(yè)概況,并結合本期鉆井規(guī)劃,歸納該油田群作業(yè)難點如下：斷層、裂縫發(fā)育,巖石易水化,易發(fā)生垮塌；井深較大：平均井深三千多米；超過四千米井多口；最大井深達到將近五千米,導致裸眼段很長,增加了井壁巖石的浸泡時間；多口井壓力系數(shù)超過平均水平,所需泥漿比重高,易壓漏地層；可鉆性差,導致機械鉆速降低,增加了裸眼的暴露時間；軌跡復雜,含大斜度長穩(wěn)斜段,易發(fā)生其它復雜情況。這些復雜情況也對井深結構的優(yōu)化選擇造成了很大困難。本文針對W12油田群存在的問題,運用測井、地質以及鉆完井資料,通過大量的調(diào)研工作,結合該研究區(qū)域鉆井工程難點和地層特征,開展W12油田群地區(qū)井壁穩(wěn)定及井身結構優(yōu)化研究。通過建立地層孔隙壓力計算模型,利用地質、錄井、鉆井、測井、測試資料,結合油田的地質情況,確定地層孔隙壓力縱向分布規(guī)律,進一步研究地層孔隙壓力橫向分布規(guī)律。通過實驗對地層坍塌周期進行了分析預測,從而研究井壁坍塌周期與鉆井液體系及鉆井液密度間的關系。最后根據(jù)W12油田群的地層孔隙壓力、破裂壓力和坍塌壓力的分布規(guī)律以地層不壓漏、不坍塌及經(jīng)濟鉆達目的層為原則,確定出該井區(qū)單井合理的井身結構。研究的過程中主要解決了以下問題：(1)油田群斷層、裂縫發(fā)育,巖石易水化,總體上講,前期井壁失穩(wěn)比較嚴重,需要弄清楚各層位發(fā)生井壁失穩(wěn)的原因,檢測那些層位易發(fā)生漏失,并精確計算地層三壓力,得到相應的壓力剖面推薦安全泥漿密度窗口,以便作業(yè)時選擇合適的泥漿比重與性能。(2)通過室內(nèi)力學實驗得到巖石力學參數(shù),并針對本地區(qū)巖石進行地應力測試及地應力剖面的確定,對該地區(qū)井壁穩(wěn)定進行評價分析。(3)油田群本期鉆井井深較大,部分井鉆遇可鉆性差地層,且軌跡復雜,裸眼暴露時間長,因此需要估算垮塌周期,得到裸眼暴露時間的極限數(shù)據(jù),為井身結構設計提供基礎數(shù)據(jù)。(4)結合地層三壓力計算結果和垮塌周期分析結果,對ODP推薦的井身結構進行優(yōu)化,以減少復雜情況的發(fā)生,降低作業(yè)成本。
[Abstract]:Wellbore stability is a very complicated problem frequently encountered in drilling engineering. W12 oilfield group is located in the Beibu Gulf basin in the west of South China Sea. In recent drilling operations, the borehole wall instability often affects the drilling speed in this area, and the W12 oilfield group is located in the Beibu Gulf basin in the western part of the South China Sea. The W12 oilfield group is a new oilfield to be developed, which plans to build several new platforms to develop and develop dozens of wells. The W12 oilfield group is a new oil field to be developed, which plans to build several new platforms to develop and develop dozens of wells due to the low operating time limit, high cost and serious influence on the progress of drilling and completion exploration. Taking a comprehensive view of the drilling operations of the adjacent wells in the early stage and combining with the drilling planning in this period, the difficulties in the operation of the oilfield group are summarized as follows: faults, fracture development, easy hydration and collapse of rocks, large depth of wells, average depth of more than 3,000 meters; The maximum depth of the well is nearly 5,000 meters, which leads to a long open hole section, which increases the immersion time of the borehole rock, and the pressure coefficient of the multiple wells exceeds the average level, the specific gravity of the mud required is high, and the formation easily lost pressure is easy to be lost. The poor drillability leads to the decrease of the mechanical drilling rate and increases the exposure time of the open hole, and the trajectory is complex and contains a long and stable slope section with large inclination, so it is easy to occur other complicated situations. These complex conditions also make it difficult to optimize the well depth structure. In view of the problems existing in W12 oilfield group, this paper uses logging, geology and drilling and completion data, through a lot of investigation work, combined with the difficulties and formation characteristics of drilling engineering in this study area. The study on wellbore stability and wellbore structure optimization in W12 oilfield group area was carried out. By establishing the calculation model of formation pore pressure, using geological, logging, drilling and testing data, combined with the geological conditions of oil field, the vertical distribution of formation pore pressure is determined, and the transverse distribution of formation pore pressure is further studied. The collapse period of formation is analyzed and predicted by experiments, so as to study the relationship between wellbore collapse period and drilling fluid system and drilling fluid density. Finally, according to the distribution law of formation pore pressure, fracture pressure and collapse pressure in W12 oilfield group, the reasonable wellbore structure of single well in this well area is determined according to the principle of formation non-pressure leakage, non-collapse and economic drilling to reach the target layer. In the course of the research, the following problems have been solved: (1) the faults of the oilfield group, the development of fractures, the easy hydration of rocks, and, in general, the serious instability of the wellbore in the early stage, so it is necessary to find out the cause of the instability of the wellbore in each stratum. The leakage of those layers is easy to occur, and the three pressure of formation is calculated accurately, and the safe mud density window is recommended by the corresponding pressure profile. In order to select suitable specific gravity and properties of mud during operation. (2) the rock mechanics parameters are obtained through laboratory mechanics experiment, and the in-situ stress test and the determination of in-situ stress profile are carried out according to the rock in this area. The wellbore stability in this area is evaluated and analyzed. (3) the depth of drilling wells in this period of oilfield group is large, some wells have poor drillability formation, and the trajectory is complex and the exposure time of open hole is long, so it is necessary to estimate the collapse period. The limit data of open hole exposure time are obtained to provide the basic data for wellbore structure design. (4) combined with the results of formation three pressure calculation and collapse period analysis, the wellbore structure recommended by ODP is optimized to reduce the occurrence of complex situations. Reduce activity-based costs.
【學位授予單位】：長江大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TE26
本文編號：2455002
[Abstract]:Wellbore stability is a very complicated problem frequently encountered in drilling engineering. W12 oilfield group is located in the Beibu Gulf basin in the west of South China Sea. In recent drilling operations, the borehole wall instability often affects the drilling speed in this area, and the W12 oilfield group is located in the Beibu Gulf basin in the western part of the South China Sea. The W12 oilfield group is a new oilfield to be developed, which plans to build several new platforms to develop and develop dozens of wells. The W12 oilfield group is a new oil field to be developed, which plans to build several new platforms to develop and develop dozens of wells due to the low operating time limit, high cost and serious influence on the progress of drilling and completion exploration. Taking a comprehensive view of the drilling operations of the adjacent wells in the early stage and combining with the drilling planning in this period, the difficulties in the operation of the oilfield group are summarized as follows: faults, fracture development, easy hydration and collapse of rocks, large depth of wells, average depth of more than 3,000 meters; The maximum depth of the well is nearly 5,000 meters, which leads to a long open hole section, which increases the immersion time of the borehole rock, and the pressure coefficient of the multiple wells exceeds the average level, the specific gravity of the mud required is high, and the formation easily lost pressure is easy to be lost. The poor drillability leads to the decrease of the mechanical drilling rate and increases the exposure time of the open hole, and the trajectory is complex and contains a long and stable slope section with large inclination, so it is easy to occur other complicated situations. These complex conditions also make it difficult to optimize the well depth structure. In view of the problems existing in W12 oilfield group, this paper uses logging, geology and drilling and completion data, through a lot of investigation work, combined with the difficulties and formation characteristics of drilling engineering in this study area. The study on wellbore stability and wellbore structure optimization in W12 oilfield group area was carried out. By establishing the calculation model of formation pore pressure, using geological, logging, drilling and testing data, combined with the geological conditions of oil field, the vertical distribution of formation pore pressure is determined, and the transverse distribution of formation pore pressure is further studied. The collapse period of formation is analyzed and predicted by experiments, so as to study the relationship between wellbore collapse period and drilling fluid system and drilling fluid density. Finally, according to the distribution law of formation pore pressure, fracture pressure and collapse pressure in W12 oilfield group, the reasonable wellbore structure of single well in this well area is determined according to the principle of formation non-pressure leakage, non-collapse and economic drilling to reach the target layer. In the course of the research, the following problems have been solved: (1) the faults of the oilfield group, the development of fractures, the easy hydration of rocks, and, in general, the serious instability of the wellbore in the early stage, so it is necessary to find out the cause of the instability of the wellbore in each stratum. The leakage of those layers is easy to occur, and the three pressure of formation is calculated accurately, and the safe mud density window is recommended by the corresponding pressure profile. In order to select suitable specific gravity and properties of mud during operation. (2) the rock mechanics parameters are obtained through laboratory mechanics experiment, and the in-situ stress test and the determination of in-situ stress profile are carried out according to the rock in this area. The wellbore stability in this area is evaluated and analyzed. (3) the depth of drilling wells in this period of oilfield group is large, some wells have poor drillability formation, and the trajectory is complex and the exposure time of open hole is long, so it is necessary to estimate the collapse period. The limit data of open hole exposure time are obtained to provide the basic data for wellbore structure design. (4) combined with the results of formation three pressure calculation and collapse period analysis, the wellbore structure recommended by ODP is optimized to reduce the occurrence of complex situations. Reduce activity-based costs.
【學位授予單位】：長江大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TE26
【參考文獻】
相關期刊論文 前2條
1 程遠方,黃榮樽;鉆井工程中泥頁巖井壁穩(wěn)定的力學分析[J];石油大學學報(自然科學版);1993年04期
2 盧運虎;陳勉;安生;;頁巖氣井脆性頁巖井壁裂縫擴展機理[J];石油鉆探技術;2012年04期
，本文編號：2455002
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