Tectonic Stress Field Analysis And Application In The Northwest Sichuan Basin

Base on two scientific research tasks that tectonic stress field analysis and Danzhai mbr oil-gas forecastin the northern Sichuan basin, and reservoir fissure distributing rule forecast in Xujiahe mbr ofXiaoxinhefeng zone of western Siehuan basin, and collecting datum and experiment, and synthesisresearch, author accomplishes ancient-nowadays tectonic stress field analysis and numerical simulationin the northwest Sichuan basin, and accomplishes reservoir fissure distributing rule forecast in Xujiahembr of Xiaoxinhefeng zone of western Sichuan basin and Danzhai mbr oil-gas forecast in the northernSichuan basin.The thesis contains five chapters. In first and second chapter, expatiate main content, theory and methodabout tectonic stress and tectonic stress field and reservoir fissure. In third chapter, studies age-oldtectonic stress field in Sichuan basin with tectonic analytical method, fissure analytical method, soundlaunch analytical method, active tectonic analytical method, focal mechanism and seism distortionanalytical method, and log analytical method, etc. In forth chapter illustrates the tectonic stress fieldnumerical simulation and reservoir fissure forecast in Xiaoxinhefeng area in western Sichuan basin. Infifth chapter, illustrates the tectonic stress field numerical simulation and reservoir fissure forecast inLangzhong area in northern Sichuan basin. And apply tectonic bending field to predict reservoir fissure.Author accomplishes a lot of loads. Such as seven-reconnaissance geology survey and joint survey andstatistical analysis, drill core observation and fissure describe in 30 wells, and choose 57 drill cores,apply sound launch survey to obtain the stress numerical of xujiahe series, sieving tectonic stressnumerical for the main tectogenetic from indosinian, and choose 200 drill cores specimen, test andsurvey the magnetic orientation and magnetic fabric distributing feature for apiece mostly tectonic layerin western Sichuan basin, accordingly study out tectonic stress field distributing feature in apiece mostlytectonic stage in Xiaoxinhefeng area. Apply imaging logging data and wall of a well inbreak statisticalanalysis to confirm nowadays tectonic stress field distributing feature, and apply reservoir fissureinterpret data statistical analysis to find the effective reservoir fissure trend approximately E-W trend.And survey the rock mechanics parameter. And apply hydraulic fracturing and logging stress explaindata to carry through regression analysis of ground stress, and study out relationship deepnessexpressions of perpendicular principal stress, level principal stress, stratum rupture press, stratum press.And apply focal mechanism solution data, seism deformation solution data, ground deformationsolution data, and active rift analysis data to analyses nowadays-tectonic stress field feature in theleading edge of Longmen Mountain. Compare with wall of a well inbreak stress analysis data ofXiaoxinhefeng area, find two trend angle warp, study and recognize it is control by the rigiditybasement in the center of Sichuan basin and the boundary domino offect of Longmen mountain mainfaults. With a great lot predecessor analysis data, study systematically the history of tectonicdeformation and the history of sediment evolvement from Triassic in Sichuan basin. Study out thetectonic movement period and tectonic stress field-distributing feature from Triassic in Sichuan basin.Synthetically think: there are seven tectonic movement stages from Triassic in Sichuan basin. Applydrilling and geophys data in Xiaoxinhefeng area and Langzhong data and the rock mechanics testanalysis data to make model for tectonic stress field numerical simulation, and completed key datetectonic stress field numerical simulation with finite meta-analysis technique. Apply numericalsimulation result data and stratum rupture analysis technology to forecast the reservoir fissure in west northern Sichuan basin and forecast the oil-gas store area, it is fine to compare with practicality drillingdata.The thesis obtains eight achievements. Summarizing the base conception and means of ground stress,tectonic stress, tectonic stress field. Base on tectonic analysis, sedimentation analysis, geophysics data,field tectonic survey data, drill cores test and experiment data, sound launch survey data, magneticfabric survey data, carry through tectogenetic substage and tectonic stress field described, and providestability matter base for tectonic simulate. Progressing with tectonic analysis of Sichuan basin. Studybasin and mountain complex coupling in Sichuan basin, Longmen Mountain, Qinglin-Daba mountain,Jiangnan ancient land and Kangdian land block. Accidence think: ancient Qinglin Ocean shut off withscissors mode indo-Chinese epoch, and forms the tectonic depositional environment of NNE～S-N trendsqueezing and NNW trend stentering. On later of indo-Chinese epoch, Longmen Mountain become foldand raise, and Jiangnan ancient land raise, and forms the tectonic depositional environment of NWWtrend squeezing. Since Yanshanian, Longmen raised fast and thrust to basin, and forms the tectonicdepositional environment of NWW～E-W trend squeezing. Progressing with magnetic fabric surveytechnology in basin analysis, to provide the main analysis means for tectonic stress filed describe.Progressing with ground stress and tectonic stress. Calculate the nowadays ground stress experienceexpressions in western Sichuan basin. It is importance datum for basin stress survey and reservoirpressing crack. The main study content of oil-gas basin tectonic stress filed:①Applying basin geologydata and earth physics data to basin tectonic analysis, obtain some data of basin and surround tectonicstress field;②Obtain tectonic stress trend and numerical value in basin varies tectonic stages;③Obtainrock mechanics parameter in varies tectonic layer in basin;④Establish the tectonic geology model withtectonic stress field analysis and reservoir analysis;⑤Carry through tectonic stress field numericalsimulation;⑥Forecast the area of reservoir fissure disturbing and oil-gas advantaged congregating.The main study way of basin tectonic stress field are geology analyses and simulate analyses. Thetraditional geology analyses way are base on tectonic stress analyses. The main basis are tectonicdeformation, rock mechanics test data, fossil organism, isotope data, math analysis, physical analogue,borehole wall inbreak analysis, sound launch analysis, focal mechanism solution, hydraulic fracturinganalysis, etc. And apply these analysis way to study tectonic stress field with time, direction andquantitative examination. Computer technology accelerate tectonic numerical simulation, and finiteelement method is one of efficiency way and become the main way of tectonic quantitative examination.The geography information system are apply in this geology analysis and cartographic enhancement onstudy course. And form a database. Information technology doesn't offer only a lot of information's, butalso become the main study way.The thesis main conclusion is about the reservoir fissure. The efficiency reservoir fissure azimuthon Xujiahe series in Xiaoxinhefeng area are near S-N trend. The fissure were formed the conjugateshear fissure on indosinian movement. They changed and reinforcement on Yanshan movement. Theirtrend are been parallel with maximize level main stress from Himalayan movement, and they keeptensional fracture regime. The E-W trend fissure system becomes the main move route way and reservespace. The reservoir fissure of Danzhai segment in Langzhong area in northern Sichuan basin arecontrol by shell rag shoal sedimentary facies. The efficiency reservoir fissure azimuth is near S-Ndirection. The fissure were formed on Yanshan movement, and later overlapped and rebuild and becomethe S-N trend fissure system. Qinglin-Daba Mountains controlled the departments tectonic. The S-Ntrend fissures are the main reserve space.