Research Institute of Petroleum Exploration and Development

Helium migration patterns in the ultra-deep reservoirs of the Anyue gas field

The Sinian–Cambrian reservoirs in the Anyue gas field contain over one trillion cubic meters of natural gas. These reservoirs are close to basement helium sources and have well-developed ancient formation water as a potential carrier. However, despite these favorable conditions,...

Origin and Source Correlation of Permian Hydrocarbons in the Kekeya Area, Southwestern Tarim Basin, China

The Southwestern Depression of the Tarim Basin has considerable petroleum exploration potential, and several hydrocarbon accumulations have been discovered in Permian reservoirs of the Kekeya area. However, the sources of Permian crude oils and the genetic types of natural gases...

Alterations in Coal Permeability and Adsorption Capacity Post Oxidation Treatment: Insights into Enhancing Coalbed Methane Production

Abstract Organic matter dissolution by oxidants can enhance the coal permeability. However, as coalbed methane (CBM) is predominantly reserved in the adsorbed state, the organic matter dissolution changes the adsorption–desorption equilibrium, thus affecting the CBM production. C...

An Improved Workflow for Shale Resource Assessment: Demonstrated Using Triassic Chang 73 Shale

Abstract In the context of energy structure transition, fossil fuels will continue to play a crucial role in the near- to medium-term future. Globally widespread shale deposits possess significant resource potential and have become key targets for energy exploration, amid growing...

Tracing Shale-Gas Migration in Complex Tectonic Settings: Evidence from Carbon-Isotope Fractionation Patterns

Abstract Late-stage tectonic deformation strongly influences shale-gas preservation and redistribution, but conventional methods rarely resolve gas-migration pathways and directions. Here, we test whether the direction of spatial carbon-isotope gradients can indicate the dominant...

Frictional characteristics and drag-reduction optimization of flexible drill strings in offshore ultrashort-radius sidetracking wells

Offshore ultrashort-radius sidetracking is an important re-entry and infill-drilling technique for exploiting remaining reserves in mature offshore fields and improving platform-based field redevelopment efficiency. However, in offshore sidetracking wells with large local curvatu...

Geochemical Characteristics and Oil–Source Correlation Analysis: A Case Study of Jurassic to Paleogene Source Rocks and Paleogene Oils in the Tajik Basin

The Tajik Basin is rich in oil and gas resources, but no analysis of the geochemical characteristics of source rocks and oil has been conducted since the Soviet era, leaving its hydrocarbon generation potential unclear. Through field outcrop sampling and organic geochemical analy...

Characteristics of Gravity Flow Deposits in the Benin Basin (Benin) and Implications for Oil and Gas Exploration

ABSTRACT In recent years, the transform passive continental margin basins in the equatorial segment of the South Atlantic have frequently yielded significant hydrocarbon discoveries, attracting widespread attention. The depositional models of gravity flows and future exploration...

Pore Pressure Prediction in Tight Sandstone Reservoirs with a Hybrid BiLSTM-CNN Model

Accurate pore pressure estimation in tight sandstone reservoirs is hampered by the limited sensitivity of conventional approaches, which rely on a single acoustic or resistivity log and assume shale undercompaction as the dominant overpressure mechanism. This study develops a hyb...

Experimental Investigation of Pressure Distribution Evolution During Water Flooding in Tight Sandstone Long Cores

Tight sandstone reservoirs are characterized by complex pore structures and ultra-low permeability, resulting in low recovery efficiency when relying solely on formation elastic energy. Consequently, water flooding is commonly employed for reservoir development. To investigate th...

Sedimentary Environment and Organic Matter Enrichment of Shale under Tectonic-Depositional Differentiation from the Lower Cambrian Niutitang Formation Guizhou, South China

Abstract To investigate variations in depositional environments and organic matter (OM) enrichment across different tectonic deformation zones, this study analyzed samples from three wells with contrasting deformation intensities: QinX1 (strongly deformed), YF1 (moderately deform...

Miocene northward expansion of the NE Tibetan Plateau via intracrustal underthrusting: insight from Cenozoic stratigraphy and provenance studies

The India–Eurasia collision and continued convergence caused significant uplift of the Tibetan Plateau and intracontinental deformation. However, how this convergence was accommodated at plateau margins remains debated, with two main models proposed: pure-shear thickening versus...

Constraints of Tectono-Hydrothermal Alteration on Permian Volcanic Reservoir Formation as Recorded by Fluid Inclusions

The origin of effective porosity in the Permian volcanic reservoirs of the Sichuan Basin remains poorly understood, particularly regarding the contribution of deep-sourced hydrothermal fluids. This study presents an integrated analysis of the Emeishan basalts, combining petrograp...

Mismatch between oil abundance and apparent displacement response in lacustrine shales: The role of wettability in the Triassic Chang 73 shale, Ordos Basin

Oil abundance alone does not fully describe displacement behavior in lacustrine shales. Here, we examine how this behavior varies with wettability. We investigated 37 core samples obtained from the third submember of the Chang 7 Member (Chang 7 3 ) of the Upper Triassic Yanchang...

Research on the Geochemical Characteristics of Quaternary Biogenic Gas Source Rocks in the Linhe Depression of the Hetao Basin: A Case Study of Well LQY1

ABSTRACT To characterize the characteristics of Quaternary biogenic gas source rocks in the Linhe Depression of the Hetao Basin, total organic carbon (TOC), Rock‐Eval pyrolysis, and gas chromatography–mass spectrometry (GC–MS) analyses were carried out on 15 samples from Well LQY...

Experimental study on chemical plugging of weakly consolidated sandstone by geothermal tailwater recharge based on artificial cores

ABSTRACT Flowchart of experimental and simulation study on chemical clogging in weakly consolidated sandstone during geothermal tailwater recharge, including artificial core reinjection tests, X-ray diffraction, ion concentration measurements, PHREEQC simulation, and resulting cl...

Evaluation of gasification agent strategies for underground coal gasification in post-ECBM reservoirs: A coupled thermo-hydro-chemical numerical simulation approach

Implementing underground coal gasification (UCG) in post-ECBM reservoirs, namely coal reservoirs after CO 2 -enhanced coalbed methane (CO 2 -ECBM) recovery, provides a potential pathway for residual energy recovery. However, the pre-existing CO 2 -rich environment alters reservoi...

Novel Technique to Enhance Hydraulic Fracture Permeability by Controllable Biomimetic Mineralization: Transitioning from Liquid Injection to Solid Propping

Abstract Unconventional oil and gas have been playing an increasingly important role in the global energy market. The primary development technique for shale and tight reservoirs is hydraulic fracturing, which aims to create high-permeability channels propped by quartz sand or ce...

Molecular Mechanisms of CTAB-Induced Oil Droplet Detachment in Shale Nanopores

Abstract The efficient recovery of shale oil is severely hindered by the strong oil–solid interactions and nanoscale confinement within shale reservoirs, which substantially restrict crude oil mobility. Although surfactant flooding has emerged as an effective enhanced oil recover...

Production prediction of shale gas reservoirs during CO2 huff-and-puff based on inflow performance relationship curves

China is endowed with abundant shale gas resources and considerable development potential; however, shale gas production frequently declines rapidly after the initial development stage. CO 2 huff-and-puff has emerged as a promising technique for enhancing shale gas recovery. To a...