Continental shale strata in China are rich in petroleum resources and are an important area to strengthen domestic oil exploration and development. Based on the latest progress in geological research and exploration and development of petroleum inside continental source kitchens of China National Petroleum Corporation exploration areas in recent two years, we have achieved the following results: (1)

The differences in organic matter abundance and rock composition between shale and mudstone determine the discrepancy of their contributions to the formation of conventional and shale oil/gas reservoirs. The evaluation criteria of source rocks are different in the future exploration in self-sourced petroleum systems. Shales are deposited in deep/semi-deep lacustrine, with low sedimentation rate and

Based on the abundant outcrops and 3D seismic data in Yuanba and its surrounding areas in northeastern Sichuan Basin, the characteristics, main controlling factors and development regularities of reservoirs in the fourth member of Sinian Dengying Formation (shortened as Deng 4 Member) were analyzed comprehensively. The results show that the reservoirs were mainly developed in microbial dolomite associated

Deep shale layer in the Lower Silurian Longmaxi Formation, southern Sichuan Basin is the major replacement target of shale gas exploration in China. However, the prediction of “sweet-spots” in deep shale gas reservoirs lacks physical basis due to the short of systematic experimental research on the physical properties of the deep shale. Based on petrological, acoustic and hardness measurements, variation

By using core, logging curves, and experiment data, favorable lithofacies types in the 2nd Member of Triassic Xujiahe Formation in the Xinchang area, Sichuan Basin were classified, standard of the favorable lithofacies was established, planar distribution regularities of the favorable lithofacies were identified, and forming mechanisms of the favorable lithofacies and their control effect on production

Based on seismic data, outcrop evidence, logging data and regional aeromagnetic data, the distribution of Nanhua–Sinian rifts in the southwestern Tarim Basin was analyzed, and on the basis of restoration of lithofacies paleogeography in different periods of Neoproterozoic–Cambrian, the evolution model of the proto-type rift basin was discussed. The Neoproterozoic Rodinia supercontinent split event

The characteristics, formation time, and origin of the sucrosic dolomite reservoirs in the Permian Qixia Formation of northwestern Sichuan Basin are analyzed. Core and outcrop description and microscopic analysis of the sucrosic dolomite samples are carried out. It is found that the dolomite has typical features different from other kinds of dolomites: (1) This dolomite is generally medium-coarse in

Under the condition of thin interbeds with great lateral changes in terrestrial basins, a seismic meme inversion method is established based on the analysis of seismic sedimentology technology. The relationship between seismic waveform and high-frequency well logs is established through dynamic clustering of seismic waveform to improve the vertical and horizontal resolution of inversion results; meanwhile

To further ascertain the origin of the Ordovician Majiagou Formation reservoirs in the Ordos Basin, the M54-M51 sub-members of the Ordovician Majiagou Formation in the eastern Sulige gasfield of Ordos Basin were taken as examples to analyze the vertical development characteristics of eogenetic karst and to discover the dissolution mechanism and its control on reservoirs through observation of a large

Drilling, seismic and logging data were used to evaluate the hydrocarbon accumulation conditions of the mound-shoal complexes in the platform margin of the fourth member of Sinian Dengying Formation in the east side of the Mianzhu-Changning intracratonic rift in the Sichuan Basin. The four understandings are: (1) The platform margin belt of the Deng 4 Member can be divided into three sections, northern

A series of theoretical explorations and field tests have been carried out to efficiently develop the Mahu tight conglomerate oilfield in the Junggar Basin. Concepts of steered-by-edge fracturing and proactive fracturing interference were proposed. A series of innovative technologies were developed and implemented including optimization of 3-D staggered well pattern, proactive control and utilization

Based on the abundant core data of oil sands in the Mackay river in Canada, the termination frequency of muddy interlayers was counted to predict the extension range of interlayers using a queuing theory model, and then the quantitative relationship between the thickness and extension length of muddy interlayer was established. An equivalent upscaling method of geologic model based on tortuous paths

Experiments of electrical responses of waterflooded layers were carried out on porous, fractured, porous-fractured and composite cores taken from carbonate reservoirs in the Zananor Oilfield, Kazakhstan to find out the effects of injected water salinity on electrical responses of carbonate reservoirs. On the basis of the experimental results and the mathematical model of calculating oil-water relative

By comparing numerical simulation results of single-porosity and dual-porosity models, the significant effect of reinfiltration to naturally fractured reservoirs was confirmed. A new governing equation was proposed for oil drainage in a matrix block under the reinfiltration process. Utilizing inspectional analysis, a dimensionless equation suitable for scaling of recovery curves for matrix blocks under

Due to engineering technology and development costs, a considerable amount of proven oil and gas resources in China are difficult to develop, becoming reserves difficult to produce. Based on the successful development of some domestic oil and gas reserves difficult to recover, this article summarizes the “four in one” petroleum engineering synergetic management model to promote the effective development

The predictions by drilling-related mechanical and geological models are in some degree inaccurate due to non-unique solution of seismic velocity model. To address this problem, a new drilling technology guided by well-seismic information integration is proposed which consists of seismic velocity update of drilled formations, seismic velocity prediction of the formation ahead of drilling bit, and the

To formulate fluids with flowback water, produced water directly to improve the utilization rate of recycling and reduce the adsorption damage of slick water to reservoirs, a high salt tolerance and low adsorption drag reducer was designed and prepared by introducing polar cation fragments to enhance the non-covalent interactions between the chains. The drag reducer was characterized by IR and NMR

The Chang 73 sub-member of Triassic Yanchang Formation in the Ordos Basin was taken as an example and the lamina types and combinations, reservoir space features and shale oil enrichment patterns in organic-rich shale strata were investigated using core observation, thin section analysis, XRF element measurement, XRD analysis, SEM, high solution laser Raman spectroscopy analysis, and micro-FTIR spectroscopy

Based on the research of the formation mechanism and evolution rule of hydrate flow obstacle during deep-water gas well testing, a new method for the prevention of hydrate flow obstacle based on safety testing window is proposed by changing the previous idea of “preventing formation” to the idea of “allowing formation, preventing plugging”. The results show that the effective inner diameter of the

Marine shale gas resources have great potential in the south of the Sichuan Basin in China. At present, the high-quality shale gas resources at depth of 2000–3500 m are under effective development, and strategic breakthroughs have been made in deeper shale gas resources at depth of 3500–4500 m. To promote the effective production of shale gas in this area, this study examines key factors controlling

Compared with marine facies shale strata, lacustrine shale strata are more complicated in geological conditions, and thus more difficult to explore and develop. To realize economic exploration and development of lacustrine shale oil, the geological regularities of accumulation and high yield of retained movable petroleum in shale should be understood first. In this work, taking the shale strata of

A set of shale-dominated source rocks series were deposited during the heyday of lake basin development in the Member 7 of Triassic Yanchang Formation, Ordos Basin, and the thickness is about 110 m. Aimed at whether this layer can form large-scale oil enrichment of industrial value, comprehensive geological research and exploration practice have been carried out for years and obtained the following

The paleotectonic pattern, lithofacies paleogeographic features, sedimentary evolution and its controlling effects on hydrocarbon accumulation assemblages during the depositional period of the Sinian Dengying Formation in middle-upper Yangtze region were investigated based on outcrops, drilling, log and seismic data. The study shows that, (1) Affected by the breakup of the Rodinia supercontinent, the

The diagenesis and diagenetic facies of shale reservoirs in Lucaogou Formation of Jimusar Sag were studied by means of microscopic observation and identification of ordinary thin sections and cast thin sections, X-ray diffraction, scanning electron microscope and electron probe tests. The results show that alkaline and acidic diagenetic processes occurred alternately during the deposition of Permian

High-yielding oil wells were recently found in the first member of Paleogene Shahejie Formation, the Binhai area of Qikou Sag, providing an example of medium- and deep-buried high-quality reservoirs in the central part of a faulted lacustrine basin. By using data of cores, cast thin sections, scanning electron microscope and physical property tests, the sedimentary facies, physical properties and main

Through lithofacies analysis and architecture anatomy of the Carboniferous Ross Sandstone turbidites outcropped at western Ireland, the depositional model of deepwater turbidite lobes is established. Seven types of lithofacies are recognized including goniatites-rich shale, laminated shale, laminated siltstone, massive sandstone, fine-medium sandstone with mud-clast, basal gravel, and chaotic mudstone

Ancient marine carbonates experienced complex modifications, making it difficult to identify reservoir genesis and effective porosity before hydrocarbon migration. To solve these issues, we used element mapping and carbonate mineral laser U-Pb radiometric dating techniques to study the diagenetic environments based on geochemistry and diagenesis-porosity evolution based on geochronology of the dolomite

The concept and characteristics of fluvial fan are elucidated through literature review and case analysis. Firstly, the concept and terminology of fluvial fan are introduced. Secondly, the progress and controversy on the formation mechanism, analysis methods and sedimentary models of fluvial fan are elaborated, and fluvial fan is compared with alluvial fan, river and lacustrine delta. Finally, ten

Carboniferous carbonate reservoirs at the eastern edge of the Pre-Caspian Basin have undergone complex sedimentation, diagenesis and tectonism processes, and developed various reservoir space types of pores, cavities and fractures with complicated combination patterns which create intricate pore-throats structure. The complex pore-throat structure leads to the complex porosity-permeability relationship

Low maturity coal samples were taken from the Ordos Basin to conduct gold tube thermal simulation experiment in a closed system, and the characteristics of the products were analyzed to find out the fractionation mechanism of carbon isotopes and the causes of abnormal carbon isotopic compositions of natural gas. At the heating rates of 2 °C/h (slow) and 20 °C/h (rapid), the low maturity coal samples

Based on well test interpretation, production performance analysis, overburden permeability and porosity test, gas-water core flooding test and high-pressure mercury injection, a quantitative correlation has been built of in-situ effective permeability with routine permeability and water saturation, and the ranges of Main Flow Channel Index (MFCI) are determined for different permeability levels in

Based on the characteristics of injection-production units in fractured-vuggy carbonate reservoirs, nine groups of experiments were designed and performed to analyze the interference characteristics and their influencing factors during water flooding. Based on percolation theory, an inversion model for simulating waterflooding interferences was proposed to study the influence laws of different factors

Based on long-term dynamic tracing of dissolved inorganic carbon (DIC) and stable carbon isotope (δ13CDIC) in produced water from 20 coalbed methane (CBM) wells in western Guizhou, the spatial-temporal dynamic variations of δ13CDIC of the GP well group produced in multi-layer commingled manner were analyzed, and the relationship between the value of δ13CDIC and CBM productivity was examined. The produced

A deep learning method for predicting oil field production at ultra-high water cut stage from the existing oil field production data was presented, and the experimental verification and application effect analysis were carried out. Since the traditional Fully Connected Neural Network (FCNN) is incapable of preserving the correlation of time series data, the Long Short-Term Memory (LSTM) network, which

A large data bank of more than 700 gas-condensate samples collected from literature and experiments was established. On this basis, empirical correlations and equations of state commonly used to calculate dew-point pressure (DPP) were evaluated. A new model for estimating DPP was proposed. All the empirical correlations and the Peng-Robinson state equation were compared, and sensitivity of parameters

This article outlines the development of separated zone oil production in foreign countries, and details its development in China. According to the development process, production needs, technical characteristics and adaptability of oilfields in China, the development of separate zone oil production technology is divided into four stages: flowing well zonal oil production, mechanical recovery and water

The main area of the Jiaoshiba anticline of the Fuling shale gas field was taken as the research object, laboratory rock mechanical experiments and direct shear experiments were conducted to clarify the mechanical anisotropy characteristics and parameters of rock samples with rich beddings. Based on the experimental results, a 3D fracture propagation model of the target reservoir taking mechanical

AM-AMPS-TAC polymers with different charge distribution are synthesized using acrylamide (AM), 2-acrylamido-2-methylpropanesulfonate (AMPS) and 3-acrylamidopropyl trimethylammonium (TAC) at different feed ratios by polymerization in solution. The salt-responsive behavior, reasons leading to salt-responsiveness, and effects of polymers molecular structure on salt-responsiveness are studied by laboratory

Based on detailed core description and systematic joint test data, enrichment laws of continental shale oil have been examined deeply. Key technologies such as the identification and quantitative evaluation method for sweet spot, precise design and tracking of horizontal well trajectory, and the low-cost horizontal well volume fracturing technology of the whole process “slick water + quartz sand” for

Pure shales in the first member of Qingshankou Formation (simplified as Qing 1 Member) in the southern Songliao Basin, i.e., the semi-deep and deep lacustrine shales, are characterized by a high content of clay minerals and poor hydrocarbon mobility, making the development of shale oil difficult. According to the drilling and testing results, the shale of Qing 1 Member can be classified into 3 lithofacies

Based on the latest geological, seismic, drilling and outcrop data, we studied the geological structure, tectonic evolution history and deformation process of the southwestern Sichuan fold-thrust belt to find out the potential hydrocarbon exploration areas in deep layers. During key tectonic periods, the southwestern Sichuan fold-thrust belt developed some characteristic strata and structural deformation

Large-scale gas accumulation areas in large oil-gas basins in central and Western China have multiple special accumulation mechanisms and different accumulation effects. Based on the geological theory and method of natural gas reservoir formation, this study examined the regional geological and structural background, formation burial evolution, basic characteristics of gas reservoirs, and fluid geology

The origin of overpressure and its effect on petroleum accumulation in the large Permian/Triassic conglomerate oil province in the Mahu Sag, Junggar Basin have been investigated based on comprehensive analysis of log curve combinations, loading-unloading curves, sonic velocity-density cross-plot, and porosity comparison data. The study results show that there are two kinds of normal compaction models

Based on analysis of NMR T2 spectral characteristics, a new method for identifying fluid properties by decomposing T2 spectrum through signal analysis has been proposed. Because T2 spectrum satisfies lognormal distribution on transverse relaxation time axis, the T2 spectrum can be decomposed into 2 to 5 independent component spectra by fitting the T2 spectrum with Gauss functions. By analyzing the

Through field geologic survey, fine interpretation of seismic reflection data and analysis of well drilling data, the differential deformation, tectonic transfer and controlling factors of the differential deformation of the Gumubiezi Fault (GF) from east to west have been studied systematically. The study shows that GF started to move southward as a compressive decollement along the Miocene gypsum-bearing

Based on comprehensive analysis of core, cast thin section, logging and seismic data, the sedimentary and reservoir architectures of the MB1-2 sub-member of Mishrif Formation in Halfaya Oilfield, Iraq, are studied. The MB1-2 sub-member of Mishrif Formation has three types of microfacies, lagoon, bioclastic shoal, and tidal channel, and facies architecture controlled by sequence stratigraphy. In the

The influence of water on gas generation from humic type organic matter at highly to over mature stage was investigated with thermal simulation experiments at high temperature and pressure. The result of the experiments indicates that the effect of water on gas generation was controlled by the thermal maturity of organic matter. Water could enhance gas generation and increase hydrocarbon gas yields

Layering detection is an important step in petroleum engineering. Time series of post-stack seismic data and wire-line log data belong to subsurface layering. They exhibit multifractal properties with complex patterns because of the heterogeneity and different genetic properties in the earth layers. In a multifractal configuration, any piece of a series has a distinct Hurst exponent that reflects its

The Duvernay project in Canada was taken as an example to summarize the advanced technology and engineering management model of shale oil and gas development in North America. Preliminary suggestions were put forward to accelerate the commercial development of domestic continental shale oil and gas. The advanced technologies, valuable knowledge and rich experience were introduced, including the evaluation

By using salt dissolution experiment, imbibition experiment and high temperature and high pressure nuclear magnetic resonance (NMR) on-line test, the evaluation methods for salt dissolution of inter salt shale oil-bearing cores were established, and the effects of salt dissolution on spontaneous imbibition and permeability were analyzed. The intensity of salt dissolution is quantitatively evaluated

Tight oil reservoir development is faced with the key technical problem that “water cannot be injected and oil cannot be produced” yet. With the diphenyl ethers water-soluble (gemini) surfactants as water phase shell and C10–C14 straight-chain hydrocarbon compounds as oil phase kernel, a nanofluids permeation flooding system was prepared by microemulsion technology, and its characteristics and EOR

In view of high oil viscosity at high temperatures, slow steam chamber expansion rate, low oil rate, and low oil/steam ratio of domestic super heavy oil blocks developed with dual-horizontal well steam assisted gravity drainage (SAGD), the solvent-aided oil viscosity reduction tests were carried out, based on which the analytical equations and similarity laws of solvent-expanded SAGD (ES-SAGD) were

It is difficult to build an effective water flooding displacement pressure system in the middle section of a horizontal well in an ultra-low permeability sandstone reservoir. To solve this problem, this study proposes to use packers, sealing cannula and other tools in the same horizontal well to inject water in some fractures and produce oil from other fractures. This new energy supplement method forms

The effects of gravity, capillary force, and viscous force on the migration characteristics of oil and gas interface in oxygen-reduced air-assisted gravity drainage (OAGD) were studied through a two-dimensional visualization model. The effects of bond number, capillary number and low-temperature oxidation on OAGD recovery were studied by long core displacement experiments. On this basis, the low-temperature

The feasibility of gas kick early detection outside the riser was analyzed based on gas-liquid multiphase flow theory. Then an experimental platform for gas kick early detection based on Doppler ultrasonic wave was established and the propagation experiments in two-phase flow of gas-water (sucrose solutions) were conducted. The time and frequency domains of the Doppler ultrasonic wave signals during

Most multiphase flow separation detection methods used commonly in oilfields are low in efficiency and accuracy, and have data delay. An online multiphase flow detection method is proposed based on magnetic resonance technology, and its supporting device has been made and tested in lab and field. The detection technology works in two parts: measure phase holdup in static state and measure flow rate

Considering the complicated interactions between temperature, pressure and hydration reaction of cement, a coupled model of temperature and pressure based on hydration kinetics during deep-water well cementing was established. The differential method was used to do the coupled numerical calculation, and the calculation results were compared with experimental and field data to verify the accuracy of

Continental shale oil is a general term for liquid hydrocarbons and many kinds of organic matter in continental organic-rich shale series with vitrinite reflectance of more than 0.5% at buried depth of more than 300 m, and is an important type of source-rock oil and gas. Based on the evolution model of oil generation and expulsion in organic-rich shale series controlled by maturity, continental shale

Based on thin-section, argon-ion polished large-area imaging and nano-CT scanning data, the reservoir characteristics and genetic mechanisms of the Lower Silurian Longmaxi shale layers with different laminae and laminae combinations in the Sichuan Basin were examined. It is found that the shale has two kinds of laminae, clayey lamina and silty lamina, which are different in single lamina thickness

Abstract The shales in the 2nd Member of Shanxi Formation in the east margin of the Ordos Basin were deposited in a marine-nonmarine transitional environment during the Permian. Based on the recent breakthroughs in the shale gas exploration and theoretical understandings on the shale gas of the study area, with a comparison to marine shale gas in the Sichuan Basin and marine-nonmarine transitional