Geophysical evaluation methods for buried hill reservoirs in the Jiyang superdepression of the Bohai Bay basin, eastern China

The Jiyang superdepression is one of the richest hydrocarbon accumulations in the Bohai Bay basin, eastern China. Comprehensive seismic methods have been used in buried hill exploration in Jiyang to describe these fractured reservoirs better. Accurate seismic stratigraphic demarcation and variable-velocity mapping were applied to reveal the inner structure of the buried hills and determine the nature of the structural traps more precisely. Based on the analysis of rock properties and the characteristics of well-developed buried hill reservoirs, we have successfully linked the geology and seismic response by applying seismic forward technology. Log-constrained inversion, absorption coefficient analysis and tectonic forward-inversion with FMI loggings were applied to analyse and evaluate the buried hill reservoirs and gave satisfying results. The reservoir prediction was successful, which confirmed that the comprehensive utilization of these methods can be helpful in the exploration of buried hill reservoirs.

A unified criterion for initiation of sediment motion and inception of sheet flow under water waves

A unified criterion is developed for initiation of non-cohesive sediment motion and inception of sheet flow under water waves over a horizontal bed of sediment based on presently available experimental data. The unified threshold criterion is of the single form, U-o = 2 pi C[1 + 5(T-R/T)(2)](-1/4), where U-o is the onset velocity of sediment motion or sheet flow, T is wave period, and C and T-R are the coefficients. It is found that for a given sediment, U-o initially increases sharply with wave period, then gradually approaches the maximum onset velocity U-o = 2 pi C and becomes independent of T when T is larger. The unified criterion can also be extended to define sediment initial motion and sheet flow under irregular waves provided the significant wave orbital velocity and period of irregular waves are introduced in this unified criterion.

Triterpane and sterane biomarkers in the YA13-1 condensates from Qiongdongnan Basin, South China Sea

Triterpanes and steranes in condensates from the YA13-1 gas field, Qiongdongnan Basin, were monitored. The YA13-1 condensates have unusual biomarker distributions dominated by terpanes and steranes derived from higher plants. Anomalously abundant 1 got-oleanane and remarkably abundant bicadinanes are present in the YA13-1 condensates, whereas the 17alpha-hopane contents are extremely low. Taraxastane and significantly abundant 17alpha-diahopanes occur in the condensates. In addition, a number of unknown C-29 and C-30 pentacyclic triterpanes including previously unreported compounds were detected in the condensates, some of which are significantly abundant. The unknown compounds may be terrestrial biomarkers. C-29 homologues are relatively predominant among the regular and rearranged steranes. The diasterane concentrations are markedly higher than those of regular steranes. The maturity of the YA13-1 condensates is relatively high, at the peak to late oil generation stage (corresponding to 0.85-1.10% Ro), based on sterane and terpane and including bicadinane maturity parameters (i.e. T/(T-1 + R) and 2T/R bicadinane ratios). The above maturity assessment result is different from that based on diamondoid maturity parameters (%Ro = 1.60-1.70) [Org. Geochem. 25 (1996) 179], which can be explained by a contribution of hydrocarbons from two sources at different depths. The YA13-1 condensates were probably generated from the Yacheng and Lingshui coal-bearing source rocks buried both in the Qiongdongnan Basin (3400-5000 m) and in the Yinggehai Basin (>5000 m). The possible contribution of lower maturity hydrocarbons from the Yacheng and Lingshui Formations (3400-4100 m) in the Qiongdongnan Basin to the YA13-1 gases and condensates should not be neglected. (C) 2003 Elsevier Science B.V. All rights reserved.

提高勘探成熟区地震资料精度的方法研究

With the Oil field exploration and exploitation, the problem of supervention and enhaning combination gas recovery was faced.then proposing new and higher demands to precision of seismic data. On the basis of studying exploration status,resource potential,and quality of 3D seismic data to internal representative mature Oil field, taking shengli field ken71 zone as study object, this paper takes advantage of high-density 3D seismic technique to solving the complex geologic problem in exploration and development of mature region, deep into researching the acquisition, processing of high-density 3D seismic data. This disseration study the function of routine 3D seismic, high-density 3D seismic, 3D VSP seismic,and multi-wave multi-component seismic to solving the geologic problem in exploration and development of mature region,particular introduce the advantage and shortage of high-density 3D seismic exploration, put forward the integrated study method of giving priority to high-density 3D seismic and combining other seismic data in enhancing exploration accuracy of mature region. On the basis of detailedly studying acquisition method of high-density 3D seismic and 3D VSP seismic,aming at developing physical simulation and numeical simulation to designing and optimizing observation system. Optimizing “four combination” whole acquisition method of acquisition of well with ground seimic and “three synchron”technique, realizing acquisition of combining P-wave with S-wave, acquisition of combining digit geophone with simulation geophone, acquisition of 3D VSP seismic with ground seimic, acquisition of combining interborehole seismic,implementing synchron acceptance of aboveground equipment and downhole instrument, common use and synchron acceptance of 3D VSP and ground shots, synchron acquisition of high-density P-wave and high-density multi-wave, achieve high quality magnanimity seismic data. On the basis of detailedly analysising the simulation geophone data of high-density acquisition ,adopting pertinency processing technique to protecting amplitude,studying the justice matching of S/N and resolution to improving resolution of seismic profile ,using poststack series connection migration,prestack time migration and prestack depth migration to putting up high precision imaging,gained reliable high resolution data.At the same time carrying along high accuracy exploration to high-density digit geophone data, obtaining good improve in its resolution, fidelity, break point clear degree, interbed information, formation characteristics and so on.Comparing processing results ,we may see simulation geophone high-density acquisition and high precision imaging can enhancing resolution, high-density seismic basing on digit geophone can better solve subsurface geology problem. At the same time, fine processing converted wave of synchron acquisition and 3D VSP seismic data,acquiring good result. On the basis of high-density seismic data acquisition and high-density seismic data processing, carry through high precision structure interpretation and inversion, and preliminary interpretation analysis to 3D VSP seismic data and multi-wave multi-component seismic data. High precision interpretation indicates after high resolution processing ,structural diagram obtaining from high-density seismic data better accord with true geoligy situation.

碳酸盐岩缝洞型储层地球物理响应特征及预测方法研究

Proven by the petroleum exploration activities, the karsts-fissure reservoir in carbonate rocks is significant to find out the large scale oil & gas field. They are made up of the four reservoir types: karsts-cave, karsts-crack, crack-cave and fracture-pore-cave. Each reservoir space and each reservoir bed has different features of reservoir heterogeneity and small scale of pore-crack-cave. The fracture-cave reservoir in carbonate rocks is characteristic by multi-types and long oiliness well. The reservoir shape is controlled by the irregular pore-crack-cave. The development level of fracture and karst-cave is the key element of hydrocarbon enriching, high productivity and stable production. However, most of Carbonate formation are buried deeply and the signal-ration-noise of seismic reflection are very low. It is reason why the fracture-cave reservoir are difficult to be predicted effectively. In terms of surveyed and studied lots of the former research outcome, The author applied the methods of synthetical reservoir geophysical prediction from two ways including macrosopic and microcomic technics in terms of the reservoir-cap condition, geophysics and geology feature and difficulty of prediction in carbonate rocks. It is guiden by the new ideas of stratigraphy, sedimentology, sedimentography, reservoir geology and karst geology. The geophysics technology is key technics. In aspects of macroscopic studies, starting off the three efficiencies of controlling the reservoir distribution including sedimental facies, karst and fracture, by means of comprehensive utilization of geology, geophysics, boring well and well log, the study of reservoir features and karst inside story are developed in terms of data of individual well and multiple well. Through establishing the carbonate deposition model, karstic model and fracture model, the macro-distribution laws of carbonatite are carried out by the study of coherence analysis, seismic reflection feature analysis and palaeotectonics analysis. In aspects of microcosmic studies, starting off analysis in reservoir geophysical response feature of fracture and karst-cave model according to guidance of the macroscopic geological model in carbonate reservoir, the methods of the carbonate reservoir prediction are developed by comprehensively utilization of seismic multi-attribution intersection analysis, seismic inversion restricted by log, seismic discontinuity analysis, seimic spectrum attenuation gradient, moniliform reflection feature analysis and multiparameter karst reservoir appraisement.Through application of carbonate reservoir synthetical geophysics prediction, the author r successfully develops the beneficial reservoir distribution province in Ordovician of Katake block 1in middle Tarim basin. The fracture-cave reservoir distributions are delineated. The prospect direction and favorable aims are demonstrated. There are a set of carbonate reservoir prediction methods in middle Tarim basin. It is the favorable basic technique in predicting reservoir of the Ordovician carbonate in middle Tarim. Proven by exploration drilling, the favorable region of moniliform reflection fracture and pore-cave and cave-fracture in lower-middle Ordovician are coincidence with the region of hydrocarbon show. It’s indicated that the reservoir prediction methods described in the study of Ordovician carbonate formation are feasible practicably.

地质导向钻井关键技术及方法

On the basis of analyzing the principle and realization of geo-steering drilling system, the key technologies and methods in it are systematically studied in this paper. In order to recognize lithology, distinguish stratum and track reservoirs, the techniques of MWD and data process about natural gamma, resistivity, inductive density and porosity are researched. The methods for pre-processing and standardizing MWD data and for converting geological data in directional and horizontal drilling are discussed, consequently the methods of data conversion between MD and TVD and those of formation description and adjacent well contrast are proposed. Researching the method of identifying sub-layer yields the techniques of single well explanation, multi-well evaluation and oil reservoir description. Using the extremum and variance clustering analysis realizes logging phase analysis and stratum subdivision and explanation, which provides a theoretical method and lays a technical basis for tracing oil reservoirs and achieving geo-steering drilling. Researching the technique for exploring the reservoir top with a holdup section provides a planning method of wellpath control scheme to trace oil and gas reservoir dynamically, which solves the problem of how to control well trajectory on condition that the layer’s TVD is uncertain. The control scheme and planning method of well path for meeting the demands of target hitting, soft landing and continuous steering respectively provide the technological guarantee to land safely and drill successfully for horizontal, extended-reach and multi-target wells. The integrative design and control technologies are researched based on geology, reservoir and drilling considering reservoir disclosing ratio as a primary index, and the methods for planning and control optimum wellpath under multi-target restriction, thus which lets the target wellpath lie the favorite position in oil reservoir during the process of geo-steering drilling. The BHA (bottomhole assembly) mechanical model is discussed using the finite element method, and the BHA design methods are given on the basis of mechanical analyses according to the shape of well trajectory and the characteristics of BHA’s structure and deformation. The methods for predicting the deflection rate of bent housing motors and designing their assemblies are proposed based on the principle of minimum potential energy, which can clearly show the relation between the BHA’s structure parameters and deflection rate, especially the key factors’ effect to the deflection rate. Moreover, the interaction model between bit and formation is discussed through the process of equivalent formation and equivalent bit considering the formation anisotropy and bit anisotropy on the basis of analyzing the influence factors of well trajectory. Accordingly, the inherence relationship among well trajectory, formation, bit and drilling direction is revealed, which lays the theory basis and technique for predicting and controlling well trajectory.

柴达木盆地地震勘探关键技术研究

The rugged surface topography determined the seismic data acquisition construction conditions and the seismic wave explosive and receiver quality in Qaidam Basin. This dissertation systematically researched the seismic acquisition, imaging process and the attribute analysis techniques of complicated oil and gas reservoir. The main research achievements and cognitions are as follows: 1. Through the stimulation effects research and analysis from the aspect of lithologic water-containing differences, it’s specific that stable hydrous sand layer can effectively enhance the stimulation effects combined with the corresponding field tests. The seismic data S/N ratio has been improved due to the combination explosive stimulation. Through the fold number and maximum offset analyses of target horizon, the complicated geometry has been optimized and the S/N ratio of seismic data has been improved, which made an important basis for improvement of 3D seismic data. 2. It has been proved that the first arrival refraction static correction method under the model constraint of fine surface survey is suitable to the Qaidam Basin of western areas by the real seismic data processing. Although the refraction horizon of near surface has some changes in a certain extent, it’s steady basically. The refraction horizon can be continuously traced in sections, so it’s qualified for the refraction static correction method on the whole. 3. The research is based on the curved-ray pre-stack time migration techniques of rough topography, and improved the imaging precision of complex areas. This techniques adopted the constant and variable velocity scanning mode and enhanced the velocity analysis precision. The 3D pre-stack time migration techniques reasonably solved the imaging and velocity multiple solutions problems of steep-dip faults and the intersections of horizontal layers. What’s more, fine velocity analysis and mute are very important to enhance the imaging precision of the seismic data in complicated Wunan areas. 4. The 3D seismic data edge-preserving processing methods have been realized due to the image process techniques. Because this method uses the large range filter, it can attenuate the noise maximally. The faults, break points, lithologic pinchout points and lithologic body of small scale such as river will not be influenced by blur because of the edge-preserving characterization of the method which is really an effective assistant technique of low S/N ratio seismic data attribute analysis. 5. The use of spectral decomposition technique can effectively identify the reservoirs. The special geology body which will not be identified (or without obvious characters) in the seismic profile may be found through the details changes of different frequencies in the amplitude profiles.

构造复杂区变速成图方法研究

In the complex structure areas, velocity field building and structure mapping are important for seismic exploration. With the development of seismic exploration, the methods of structure mapping, reservoir prediction and reservoir description all require high precious velocity field. And more accurate depth-structure maps are required for well site design. Aiming at the problems and defects in velocity analysis and structure mapping in oil seismic exploration, the paper which is based on the studies of real data in several areas combines the theories with practical application, and analyzes the precision and applicability of several methods of velocity model building. After that, the following methods are mainly studied: the coherence inversion methods based on the pre-stack CMP gathers or stacking velocity; the interval velocity inversion methods constrained by multi-well; the Random Simulation method; 3D Image Ray Map Migration method and the structure mapping in floating datum and in fixed datum, and then we conclude the method of building high precious seismic velocity field and structure mapping with variable velocity. Firstly, the paper analyses the distributing rule of the velocity variation in the areas with complex structures in the northwest of China, then points out that velocity is a crucial factor which influences the precision of structure mapping, and the velocity variations have something to do with the shapes of the structures, the variety of lithology and so on. The key point of improving the precision of seismic velocity field is to obtain a structure mapping with high precision. We also describe the range and conditions of these methods. Secondly, by comparing many popular methods of velocity model building, we propose a new method in the use of velocity model building. The new method is more effective in velocity model building under every kind of complex condition and is worthy of spreading. At last, the paper fingers out that it is a system engineering to study variable velocity mapping in every kind of complex structure areas. Every step of the work can affect the final results. So it is important to build high efficient and practical velocity model and the flows of mapping processing. The paper builds the flows and gives some examples. The method has been applied in more than ten exploring surveys. The application proves that this method could bring good effect on researching on low-amplitude trap, reservoir prediction, reservoir description and the integrated research of oil&gas geology. Keywords: structure mapping velocity model building complex structure variable velocity media

大港油田复杂断块油气藏评价技术研究与应用

In this paper, in view of characteristics and appraisal difficulty of complicate fault block reservoir, based on the theory of reservoir geology, tectonic geology, sequence stratigraphy, logging geology and sedimentology, according to related multidisciplinary data, such as geological, geophysical, logging and testing, taking 3D seismic acquisition processing, delicate structure interpretation, fine reservoir prediction, reservoir engineering and logging evaluation as research methods, on the basis of comprehensive geologic research, innovative appraisal thinking of complicate fault block reservoir is probed into, reservoir evaluation technology series of different reservoirs were created, and appraisal circuit of complicate fault block reservoir was proposed. According to the research on main controlling factors of hydrocarbon and concentration and concealing laws of Dagang exploration area, family assemble patterns of complicate fault block reservoir were proposed firstly, such as twinning, juxtaposed, overlying, concurrent, connected in series and so on, so theory basement was provided to reservoir evaluation. Taking into account of difficulties of low signal to noise ratio and border identification of lithologic trap of complicate fault block reservoir, in the middle of seismic data acquisition, double focusing layout and optimization technology were adopted, geophysical model was set up, and best observation system was ascertained. During object processing, matching processing technology of removing time difference, phase difference, energy difference and frequency spectrum difference generated by different blazing and receiving elements was studied. Imagery, low amplitude structure and identification of subtle lithologic reservoir was interpreted reasonably. On the basis of characteristics and technical description analysis of structural, structural--lithologic and lithologic reservoirs, innovative appraisal thinking of these reservoirs was formatted, appraisal circuit of complicate fault block reservoir was proposed, and this method could be used in other similar oilfields

全信息精细储层预测方法研究与实践-以周清庄油田沙三段油藏为例

With the continuously proceeding of petroleum exploratory development in China, exploratory development becomes more and more difficult. For increasing reserve volume and production, lithologic hydrocarbon reservoir has been the most workable, potential and universality exploration targets. In the past, Dagang Oil Field use the complicated fault reservoir theory as the guide, develop and form a suit of matching construction and instrument in prospecting complicated fault reservoir that reach top of exploration industry in China. But the research of lithologic hydrocarbon reservoir is not much, which affects the exploitation progress of lithologic hydrocarbon reservoir. In this thesis, is object, through the depth study of lithologic deposition in Shasan segment of Zhouqingzhuang Oil Field, a suit of holographic fine reservoir bed forecasting techniques is built up and finally gets following main results: 1. Applying geology, seism, drilling, logging and other information to sensitivity preferences, geological model, inversion and integrated stratum evaluation, realizing the method and flow of refined multi-information stratum forecast. 2. Built up a full three dimensional fine structural interpretation method: in view of r problem of accurately demarcating 90% inclined well, propose a inclined well air space demarcating method, make bed demarcating more exactly; in view of problem of faults demarcating and combination in seismic interpretation, propose a computational method of seismic interference based on wavelet translation, make identify the fault in different level more dependable and reasonable; for exactly identifying structural attitude, propose a velocity modeling method under multi-well restriction, make structural attitude closer to the facts. 3. Built up a high accuracy reservoir bed inversion method: in view of problem in exactly identifying reservoir and nonreservoir with conventional wave impedance inversion method in this place, propose a reservoir log response characteristic analysis and sensible log parameter inversion method. ①analysis log response of reservoir and nonreservoir in region of interest, make definite the most sensible log parameter in identifying reservoir and nonreservoir in this region; ②make sensible log parameter inversion based on wave impedance inversion, to improve inversion accuracy, the thickness of recognizable reservoir bed reach 4-5m. 4. Built up a 4-D reservoir forcasting circuit: in view of difficulty that in lithologic hydrocarbon reservoir making reservoir space characteristic clear by using structural map and reservoir forecasting techniques once only, propose a 4-D reservoir forcasting circuit. In other words, based on development conceptual design, forcast reservoir of different time, namely multiple 3D reservoir forcasting in time queue, each time the accuracy degree of reservoir forcasting is improved since apply the new well material, thereby achieve high quality and highly efficient in exploratory development. During exploratory development lithologic depositin in Shasan segment of Zhouqingzhuang Oil Field, there are thirteen wells get 100% success rate, which sufficiently proves that this suit of method is scientific and effective.

辽河坳陷东部凹陷火山岩构造裂缝形成机理研究及预测

In recent years, with the discovery oil and gas reservoirs in volcanic rocks, the exploration and development of these reservoirs have attracted widespread attention because of the urgent need for increasing oil and gas production in the world and volcanic rocks has currently become an important exploration target in Liaohe depression. The study area of this dissertation is in the middle section of the easternern sag of Liaohe depression that have been confirmed by studying structural fractures, which constitute a key factor impacting volcanic rocks reservoirs. Substantial reserves and large production capacity in the areas with widely distributed volcanic rocks are important reasons for examining volcanic rocks in the study area. The study began with classification and experimental data analysis of volcanic rocks fractural formation, then focused on the mechanism of fracturing and the development of volcanic rocks structural fracture prediction methodology.and Lastly, predicted volcanic rocks structural fracture before drilling involved a comprehensive study of the petroleum geology of this area, which identified favorable traps thereby reducing exploration risks and promoting the exploration and development of volcanic rocks reservoirs. 3Dstress and 3Dmove software were applied to predict structural fracture by combining the core data, well-logging data and seismic data together and making the visualization of a fracture possible. Base on the detailed fracture prediction results, well OuO48 and well Ou52 were drilled and successfully provided a basis for high efficiency exploration and development of fractured reservoir in the middle section of the eastern sag. As a result of what have been done, a new round of exploration of volcanic rocks was developed. Well OU48 and well OU52 successfully drilled in this area resulted in the in-depth study of the mechanism of structural fracture formation, technological innovation of structural fracture prediction of volcanic rocks , which guided to oil and gas exploration effectively and made it possible for high production of volcanic rocks. By the end of August 2005, the cumulative oil and gas production of Ou48 block were 5.1606 × 104 t and 1271.3× 104 m3 respectively, which made outstanding contributions to the oilfield development. Above all this work not only promoted exploration and structural fracture prediction in volcanic rocks in Liaohe depression, but also applied to in the low-permeability and fractured sandstone reservoir.

碎屑岩储层低电阻率油层识别方法与应用——以济阳坳陷为例

So far, there is no methods of logging interpretation effective enough to identify a low resistivity payzone since its resistivity value almost equals to that of an aquifer although many low-resistivity payzones have been found in lots of petroliferous basins worldwide. After a thorough study on those technical difficulties of the logging interpretation for the low-resistivity payzones, some corresponding resolutions have been put forward in this paper. In order to reveal its microscopic mechanism, researches on the discovered low-resistivity payzones have been carried on with analyses of core and lab test data, thus main influencing factors of the low-resistivity reservoirs have been pointed out including conductivity minerals, clay minerals, fluids, porosity and pore structure. In order to make clear the degree of influence of those reservoir factors on resistivity logging(log), lab studies and numeral simulations have been done with the typical core and formation water samples, therefore, their influence degrees have ascertained quantitatively or semi-quantitatively. The distribution law and possible distribution areas of the low-resistivity payzones in Jiyang Depression have been figured out firstly after the macroscopic geology origins (sedimentation, dynamic accumulation process, diagenesis etc.) in the area have been studied. In order to resolve the problem of difficult logging-interpretation, methods of interpretation and identification have been brought forward creatively according to the low-resistivity payzone type ascribed to macroscopic geology laws and to the combined features of logging traces, after a systemic summary of different responses of logging caused by different microscopic mechanism. Those methods have been applied in Dongying and Huimin Sag of Shengli Exploration Area, precision of identification of the low-resistivity payzones improved effectively and good economic attraction prove their great prospect.

黄骅坳陷港西开发区河流相储层构型与剩余油分布模式研究

In the production tail of oilfield, water-cut is very high in thick channel sand oil reservoir, but recovery efficiency is relative low, and recoverable remaining oil reserves is more abundant, so these reserves is potential target of additional development. The remaining oil generally distributed with accumulation in certain areas, controlled by the reservoir architecture that mainly is the lateral accretion shale beddings in the point bar, so the study of reservoir architecture and the remaining oil distribution patterns controlled by architecture are very significant. In this paper, taking the Minghuazhen formation of Gangxi oilfield as a case, using the method of hierarchy analysis, pattern fitting and multidimensional interaction, the architecture of the meandering river reservoir is precisely anatomized, and the remaining oil distribution patterns controlled by the different hierarchy architecture are summarized, which will help to guide the additional development of oil fields. Not only is the study significant to the remaining oil forecasting, but also it is important for the theory development of reservoir geology. With the knowledge of sequence correlation and fluvial correlation model, taking many factors into account, such as combination of well and seismic data, hierarchical controlling, sedimentary facies restraint, performance verification and 3-D closure, an accurate sequence frame of the study area was established. On the basis of high-resolution stratigraphic correlation, single layer and oil sand body are correlated within this frame, and four architecture hierarchies, composite channel, single channels, point bars and lateral accretion sandbody are identified, The result indicates that Minghuazhen Formation of Gangxi oilfield are dominated by meandering river deposition, including two types of channel sandbodies, narrow band and wide band channel sandbody, and each of them has different characteristics of facies variation laterally. Based on the identification of composite channel, according to the spatial combination patterns and identified signs of single channel, combined with channel sandbody distribution and tracer material data, single channel sandbodies are identified. According to empirical formula, point-bar scales of the study area are predicted, and three identification signs are summarized, that is, positive rhythm in depositional sequence, the maximum thick sand and near close to the abandoned channel, and point bars are identified. On the basis of point bar recognition, quantitative architecture models inner point bar are ascertained, taking the lateral accretion sand body and lateral accretion shale beddings in single well as foundation, and quantitative architecture models inner point bar as guidance, and result of tracer material data as controlling, the the lateral accretion sand body and lateral accretion shale beddings are forecasted interwell, so inner architecture of point bar is anatomied. 3-D structural model, 3-D facies model and 3-D petrophysical properties models are set up, spatial distribution characteristics of sedimentary facies and petrophysical properties is reappeared. On the basis of reservoir architecture analysis and performance production data, remaining oil distribution patterns controlled by different hierarchy architecture units, stacked channel, single channel and inner architecture of point bar, are summarized, which will help to guide the additional development of oil fields.

黄骅坳陷马东地区沙河街组重力流水道储层评价及剩余油研究

In this paper, taking Madong district of Huanghua depression as a case, based on the theory of sequence stratigraphy, sedimentology, reservoir geology and geophysics, according to core analysis, seismic attribute analysis, logging constrained inversion, multi-data correlation of strata, reservoir modeling, etc. the lower and middle first member of Shahejie formation of the study area was forecasted and evaluated. As a result, a number of reservoir prediction and remaining oil distribution methods suitable to oil exploitation of gravity flow channel reservoir are presented. Scientific foundation is provided to the next adjustment of development program and exploitation of the remaining oil. According to high resolution sequence stratigraphy theory, precise stratigraphic framework was founded, the facies types and facies distribution were studied under the control of stratigraphic framework, the technologies of seismic attribute abstraction and logging constrained inversion. Result shows that gravity flow channel, as the main facies, developed in the rising period of base-level cycle, and it was formed during the phase of contemporaneous fault growth. As the channel extends, channel width was gradually widened but thickness thined. The single channels were in possession of a great variety of integrated modes, such as isolated, branching off, merging and paralleling, forming a kind of sand-mud interblending complex sedimentary units. Reservoir quality differs greatly in vertical and horizontal direction, and sedimentary microfacies is main controlling factor of the reservoir quality. In major channel, deposition thickness is great, and petrophysical property is well. While in marginal channel, reservoir is thinner, and petrophysical property is unfavorable. Structure and reservoir quality are main factors which control the oil and gas distribution in the study area. On the basis of the research about the reservoir quality, internal, planar and 3-D reservoir heterogeneities are characterized, and the reservoir quality was sorted rationally. At last, based on the research of reservoir numerical simulation of key well group, combined with reservoir performance analysis and geological analysis above, remaining oil distribution patterns controlled by internal rhythm of gravity flow channel were set up. Through this research, a facies-restrained reservoir prediction method integrating multi-information was presented, and potential orientation of remaining oil distribution in gravity flow channel reservoir is clarified.