Evaluating Efficiency of Multilateral Producing Wells in Bottom Water-Drive Reservoir with a Gas Cap by Distributed Fiber-Optic Sensors and Continuous Pressure Monitoring

Abstract The main goal of the pilot job is to assess the risks of production by horizontal wells and multilateral wells with a close gas cap above and water layers beneath the main formation. The objectives are to monitor the total producing length of the wells using temperature and pressure surveillance. The results of monitoring were analyzed at different stages of development. An analysis was carried out by combining pressure and temperature data obtained while monitoring the production of multilateral wells. The well properties were determined using RTA and PTA. To assess the inflow profile, distributed temperature sensors in the wells were analyzed for the entire period of appraisal production. A feature of the research was the low contrast of temperature anomalies associated with fluid inflow. In addition, it was also revealed that the DTS absolute readings at the depth of the formation were affected by surface temperature, which required corrections and the use of relative readings in the calculations instead of absolute ones. The main feature of the pressure analysis was the short period of production. With such well completion geometry and reservoir properties of the layer, the radial flow could not be achieved during the whole test period. Despite these limitations, the dynamics of the total producing length of the well was determined. The initial value of the producing length was about 70% of the drilled length, then there is a slight decrease after 7 to 10 months of well production. By analyzing the fiber-optic temperature profile, an inflow profile was assessed. Based on the analysis of changes in relative temperature anomalies, the shares of inflow from the sidetracks were estimated. Several memory temperature / pressure gauges set along the horizontal section were used as an additional data source to monitor well parameters during the whole period of production. The difference in their readings was due to, among other things, the average flow rate in the section between the sensors, which made it possible to give an independent assessment of the inflow profile. Based on the results of the job performed, a number of risks and uncertainties were removed, including information on the total flowing horizontal length dynamics, which is a valuable input for full-field development planning. In addition, an express method of DTS data analysis has been developed for assessing the wellbore producing length without significant temperature changes associated with intervals of inflow.

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The Arab Formation in central Abu Dhabi: 3-D reservoir architecture and static and dynamic modeling

GeoArabia ◽

10.2113/geoarabia080147 ◽

2003 ◽

Vol 8 (1) ◽

pp. 47-86 ◽

Cited By ~ 2

Author(s):

Jürgen Grötsch ◽

Omar Suwaina ◽

Ghiath Ajlani ◽

Ahmed Taher ◽

Reyad El-Khassawneh ◽

...

Keyword(s):

Dynamic Modeling ◽

Fourth Order ◽

High Energy ◽

Development Planning ◽

Abu Dhabi ◽

Small Scale ◽

Reservoir Properties ◽

Depositional Facies ◽

Well Completion ◽

Fifth Order

ABSTRACT A 3-D geological model of the Kimmeridgian-Tithonian Manifa, Hith, Arab, and Upper Diyab formations in the area of the onshore Central Abu Dhabi Ridge was based on a newly established sequence stratigraphic, sedimentologic, and diagenetic model. It was part of an inter-disciplinary study of the large sour-gas reserves in Abu Dhabi that are mainly hosted by the Arab Formation. The model was used for dynamic evaluations and recommendations for further appraisal and development planning in the studied field. Fourth-order aggradational and progradational cycles are composed of small-scale fifth-order shallowing-upward cycles, mostly capped by anhydrite within the Arab-ABC. The study area is characterized by a shoreline progradation of the Arab Formation toward the east-northeast marked by high-energy oolitic/bioclastic grainstones of the Upper Arab-D and the Asab Oolite. The Arab-ABC, Hith, and Manifa pinch out toward the northeast. The strongly bioturbated Lower Arab-D is an intrashelf basinal carbonate ramp deposit, largely time-equivalent to the Arab-ABC. The deposition of the Manifa Formation over the Arab Formation was a major back-stepping event of the shallow-water platform before the onset of renewed progradation in the Early Cretaceous. Well productivity in the Arab-ABC is controlled mainly by thin, permeable dolomitic streaks in the fifth-order cycles at the base of the fourth-order cycles. This has major implications for reservoir management, well completion and stimulation, and development planning. Good reservoir properties have been preserved in the early diagenetic dolomitic streaks. In contrast, the reservoir properties of the Upper Arab-D oolitic/bioclastic grainstones deteriorate with depth due to burial diagenesis. A rock-type scheme was established because complex diagenetic overprinting prevented the depositional facies from being directly related to petrophysical properties. Special core analysis and the attribution of saturation functions to static and dynamic models were made on a cell-by-cell basis using the scheme and honoring the 3-D depositional facies and property model. The results demonstrated the importance of integrating sedimentological analysis and diagenesis with rock typing and static and dynamic modeling so as to enhance the predictive capabilities of subsurface models.

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Significance of The Sedimentology and Stratigraphy for Identification of Low Contras Low Resistivity zones in a Clastic Outcrop of The Upper Talang Akar Formation, Musi Banyuasin, Indonesia

10.29118/ipa21-sg-290 ◽

2021 ◽

Author(s):

A. F. H. Surbakti

Keyword(s):

Clay Minerals ◽

Coarse Grained ◽

The South ◽

Reservoir Properties ◽

Low Contrast ◽

Facies Distribution ◽

Low Resistivity ◽

Different Sources

The Talang Akar Formation is one of the hydrocarbon-producing reservoirs of the South Sumatra Basin. This basin is filled from two different sources in the Eastern part and Western part paleo-high. The bottom Talang Akar consists of coarse-grained sandstone, and the upper part constrains intercalation of sandstone and shale, known as low resistivity low contrast zone (LRLC). The Talang Akar Formation from Air Batu and Sukomoro confers an excellent probability to observe and define LRLC zones over systematic approaches. This paper will provide an analogue of the LRLC reservoir zone by analyzing the relation between facies distribution and reservoir properties, including detailed shale structure. Facies distribution was obtained from the outcrop stratigraphic profile. The reservoir properties are identified by the Thomas Stieber plot and the petrographic section. Seven facies of Talang Akar Formation had been identified, which are: 1) planar cross-bedded sandstone (PCBS), 2) trough cross-bedded sandstone (TCBSS), 3) laminated sandstone (LSS), 4) heterolytic sandstone (HSS), 5) clay-rich sandstone (CSS), 6) mudstone (MS), 7) scour conglomeratic sandstone (SCSS). There are several types of shale distribution: structural shale, dispersed shale, and laminar shale. The laminar and dispersed shale consists of most of the reservoir and fills the pore. The clay structure deduces the disparity in the facies-porosity correlation. The finding of this study revealed that the LRLC zones are caused by lamination structures, thin intercalation layers, heterolytic and clay minerals.

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A geomechanical approach for sanding risk assessment applied to three field cases for completion optimisation

The APPEA Journal ◽

10.1071/aj09040 ◽

2010 ◽

Vol 50 (1) ◽

pp. 623 ◽

Cited By ~ 1

Author(s):

Khalil Rahman ◽

Abbas Khaksar ◽

Toby Kayes

Keyword(s):

Decision Making ◽

Petroleum Industry ◽

Cost Effective ◽

Development Planning ◽

Control Measures ◽

Sand Production ◽

Field Development ◽

Well Completion ◽

Sand Control ◽

Production Prediction

Mitigation of sand production is increasingly becoming an important and challenging issue in the petroleum industry. This is because the increasing demand for oil and gas resources is forcing the industry to expand its production operations in more challenging unconsolidated reservoir rocks and depleted sandstones with more complex well completion architecture. A sand production prediction study is now often an integral part of an overall field development planning study to see if and when sand production will be an issue over the life of the field. The appropriate type of sand control measures and a cost-effective sand management strategy are adopted for the field depending on timing and the severity of predicted sand production. This paper presents a geomechanical modelling approach that integrates production or flow tests history with information from drilling data, well logs and rock mechanics tests. The approach has been applied to three fields in the Australasia region, all with different geological settings. The studies resulted in recommendations for three different well completion and sand control approaches. This highlights that there is no unique solution for sand production problems, and that a robust geomechanical model is capable of finding a field-specific solution considering in-situ stresses, rock strength, well trajectory, reservoir depletion, drawdown and perforation strategy. The approach results in cost-effective decision making for appropriate well/perforation trajectory, completion type (e.g. cased hole, openhole or liner completion), drawdown control or delayed sand control installation. This type of timely decision making often turns what may be perceived as an economically marginal field development scenario into a profitable project. This paper presents three case studies to provide well engineers with guidelines to understanding the principles and overall workflow involved in sand production prediction and minimisation of sand production risk by optimising completion type.

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Horizontal wellbore production profile evaluation by distributed fiber-optic temperature surveillance

PROneft’ Proffessional’no o nefti ◽

10.51890/2587-7399-2021-6-4-81-91 ◽

2021 ◽

Vol 6 (4) ◽

pp. 81-91

Author(s):

Andrey I. Ipatov ◽

Mikhail I. Kremenetsky ◽

Ilja S. Kaeshkov ◽

Mikhail V. Kolesnikov ◽

Alexander A. Rydel ◽

...

Keyword(s):

Fiber Optic ◽

Phase Segregation ◽

Gas Production ◽

Fiber Optic Sensor ◽

Well Testing ◽

Reservoir Properties ◽

Horizontal Wellbore ◽

Long Term Monitoring ◽

Term Monitoring

The main goal of the paper is demonstration of permanent downhole long-term monitoring capabilities for oil and gas production profile along horizontal wellbore in case of natural flow. The informational basis of the results obtained is the data of long-term temperature and acoustic monitoring in the borehole using a distributed fiber-optic sensor (DTS + DAS). Materials and methods. At the same time, flowing bottom-hole pressure and surface rates were monitored at the well for rate transient analysis, as well as acoustic cross-well interference testing [1], based on the results of which “well-reservoir” system properties were evaluated, the cross-well reservoir properties of the were estimated, and the possibility of cross-well testing using downhole DTS-DAS equipment was justified. The research results made it possible to assess reliability of DTS-DAS long-term monitoring analysis results in case of multiphase inflow and multiphase wellbore content. In particular, DTS-DAS results was strongly affected by the phase segregation in the near-wellbore zone of the formation. Conclusions. In the process of study, the tasks of inflow profile for each fluid phase evaluation, as well as its changes during the well production, were solved. The reservoir intervals with dominantly gas production have been reliably revealed, and the distribution of production along the wellbore has been quantified for time periods at the start of production and after production stabilization.

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INTEGRATION OF RESERVOIR AND WELL FLOW SIMULATORS FOR ANALYSIS OF HORIZONTAL WELL PERFORMANCE

The APPEA Journal ◽

10.1071/aj06011 ◽

2007 ◽

Vol 47 (1) ◽

pp. 181

Author(s):

G. Sanchez ◽

A. Kabir ◽

E. Nakagawa ◽

Y. Manolas

Keyword(s):

Real Time ◽

Horizontal Well ◽

Pressure Profile ◽

Learning System ◽

Well Performance ◽

Reservoir Properties ◽

Well Completion ◽

Real Time Analysis ◽

Reservoir Simulator ◽

Inflow Performance

The optimisation of a well’s performance along its life cycle demands improved understanding of processes occurring in the reservoir, near wellbore and inside the well and flow lines. With this purpose, the industry has been conducting, for several years, initiatives towards reservoirwellbore coupled simulations.This paper proposes a simple way to couple the near wellbore reservoir and the wellbore hydraulics models, which contributes to the optimisation of well completion design (before and while drilling the well) and the maximisation of the well inflow performance during production phases, with support of real-time and historical data. The ultimate goal is the development of an adaptive (self-learning) system capable of integrated, real-time analysis, decision support and control of the wells to maximise productivity and recovery factors at reservoir/field level. At the present stage, the system simulates the inflow performance based on an iterative algorithm. The algorithm links a reservoir simulator to a hydraulics simulator that describes the flow inside the wellbore. The link between both simulators is based on equalisation of flow rates and pressures so that a hydraulic balance solution of well inflow is obtained. This approach allows for full simulation of the reservoir, taking into consideration the petrophysical and reservoir properties, which is then matched with the full pressure profile along the wellbore. This process requires relatively small CPU time and provides very accurate solutions. Finally, the paper presents an application of the system for the design of a horizontal well in terms of inflow profile and oil production when the production is hydraulically balanced.

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Achieving Improved Drilling Performance with Hole Cleaning Technology in Horizontal Shale Gas Wells in Sichuan Basin of China

10.2523/iptc-21214-ms ◽

2021 ◽

Author(s):

Guodong Ji ◽

Haige Wang ◽

Hongchun Huang ◽

Meng Cui ◽

Feixue Yulong ◽

...

Keyword(s):

Shale Gas ◽

Sichuan Basin ◽

Horizontal Wells ◽

Drill String ◽

Operating Parameters ◽

Optimal Operating ◽

Horizontal Section ◽

Drill Cuttings ◽

Well Completion ◽

Cuttings Bed

Abstract The horizontal section length of shale gas horizontal wells in Sichuan Basin in the south-west of China generally exceeds 2000m. Cuttings are apt to accumulate and form cuttings beds along such long and curve horizontal sections due to low cuttings carrying capacity, which often results in excessive torque and drag or even stuck pipes during drilling process. According to the statistics dada inthe period of Jan. - Oct. 2019, more than 25 stuck pipe incidents and 15 rotary steering tools loss in borehole were reported due to inefficient cuttings transportation in the long horizontal wells in Sichuan Basin. This paper studies the cuttings transportation and cuttings bed formation in horizontal wells. A prediction model for the distribution of cuttings bed was established. A monitoring and analysis software for the cuttings bed and cuttings cleaner with V-shaped spiral blades that is used to agitate the cuttings bed wasdeveloped. The software calculates the distribution and thickness of the cuttings bed according to the well trajectory, wellbore structure, drilling fluid characteristics, etc., and provides the optimal operating parameters for the removal of the cuttings bed by the rotating and reciprocating drill string. Then, the drill cuttings remover in the drill string moves to the predicted position of the drill cuttings, scrapes the drill cuttings and creates a swirling flow during the pipe rotation. The combined application of software and makeup remover can effectively solve the issue of borehole cleaning in long horizontal wells. One of the field applications was carried out in the well Ning 209H12, a shale gas horizontal well in Sichuan Basin. The well experienced excessive torque and drag issue during the tripping of drill string of long horizontal section. Thesoftware ran based on oil well data, and it determines the placement and thickness of cuttings beds in the well and calculates the optimal operating parameters for a flow rate of about 32L/s and a speed of 100rpm to remove them. By rotatingand reciprocating the drill string with recommended operating parameters along the cuttings bed interval, the removers helped cleaning the cuttings bed efficiently and significant amount of cuttings was observed at vibration screen. After cleaning the cuttings bed interval, the trip smoothly ran to the bottom without any excessive torque and drag, and then continues to drill in cooperation with the removers to the total depth. During the well completion, there was no problem with the operation of electrical logging and production casing. This cuttings removal technology has been used in other shale gas formations and tight gas formations where horizontal wells are widely used.

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World's First Extension Pack with 7-in. Enhanced Single-Trip Multizone System: Success Case and Learning Points on the Installation and Treatment Design

10.2523/iptc-21783-ms ◽

2021 ◽

Author(s):

Sunanda Magna Bela ◽

Abdil Adzeem B Ahmad Mahdzan ◽

Noor Hidayah A Rashid ◽

Zairi A Kadir ◽

Azfar Israa Abu Bakar ◽

...

Keyword(s):

Reservoir Characterization ◽

Development Planning ◽

Development Project ◽

Lessons Learned ◽

High Rate ◽

Individual Treatment ◽

Flow Area ◽

Field Development ◽

Well Completion ◽

Gravel Pack

Abstract Gravel packing in a multilayer reservoir during an infill development project requires treating each zone individually, one after the other, based on reservoir characterization. This paper discusses the installation of an enhanced 7-in. multizone system to achieve both technical and operational efficiency, and the lessons learned that enabled placement of an optimized high-rate water pack (HRWP) in the two lower zones and an extension pack in the uppermost zone. This new approach helps make multizone cased-hole gravel-pack (CHGP) completions a more technically viable and cost-effective solution. Conventional CHGPs are limited to either stack-pack completions, which can incur high cost because of the considerable rig time required for multizone operations, or alternate-path single-trip multizone completions that treat all the target zones simultaneously, with one pumping operation. However, this method does not allow for individual treatment to suit reservoir characterization. The enhanced 7-in. multizone system can significantly reduce well completion costs and pinpoint the gravel placement technique for each zone, without pump-rate limitations caused by excessive friction in the long interval system, and without any fiuid-loss issues after installation because of the modular sliding side-door (SSD) screen design feature. A sump packer run on wireline acts as a bottom isolation packer and as a depth reference for subsequent tubing-conveyed perforating (TCP) and wellbore cleanup (WBCU) operations. All three zones were covered by 12-gauge wire-wrapped modular screens furnished with blank pipe, packer extension, and straddled by two multizone isolation packers between the zones, with a retrievable sealbore gravel-pack packer at the top. The entire assembly was run in a single trip, therefore rig time optimization was achieved. The two lower zones were treated with HRWPs, while the top zone was treated with an extension pack. During circulation testing on the lowermost zone, high pumping pressure was recorded, and after thorough observation of both pumping parameters and tool configuration, it was determined that the reduced inner diameter (ID) in the shifter might have been a causal factor, thereby restricting the flow area. This was later addressed with the implementation of a perforated pup joint placed above the MKP shifting tool. The well was completed within the planned budget and time and successfully put on sand-free production, exceeding the field development planning (FDP) target. The enhanced 7-in. multizone system enabled the project team to beat the previous worldwide track record, which was an HRWP treatment only. As a result of proper fluid selection and rigorous laboratory testing, linear gel was used to transport 3 ppa of slurry at 10 bbl/min, resulting in a world-first extension pack with a 317-lbm/ft packing factor.

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A Play-Wide Performance Review of Plug and Perf, Ball and Seat, and Pinpoint Fracturing Methods in the Montney Tight Siltstone Reservoir

10.2118/205298-ms ◽

2022 ◽

Author(s):

Benyamin Yadali Jamaloei ◽

Robert Burstall ◽

Amit Nakhwa

Keyword(s):

Small Sample Size ◽

Development Planning ◽

Small Sample ◽

Water Phase ◽

Well Performance ◽

Reservoir Properties ◽

Clustering Technique ◽

Casing Deformation ◽

The Impact ◽

Lateral Length

Abstract The Montney reservoir is one of the most prolific unconventional multi-stacked dry and liquid-rich gas plays in North America. The type of fracturing method and fluid has a significant impact on water-phase trapping, casing deformation, and well performance in the Montney. Different fracturing methods (plug and perf/plug and perf with ball/ball and seat/single-entry pinpoint) and fluids (slickwater/hybrid/oil-based/energized/foam) have been tested in 4000+ Montney wells to find optimal fracturing method and fluid for different reservoir qualities and fluid windows and to minimize water-phase trapping and casing deformation. The previous studies reviewing the performance of fracturing methods in Montney do not represent a holistic evaluation of these methods, due to some limitations, including: (1) Using a small sample size, (2) Having a limited scope by focusing on a specific aspect of fracturing (method/fluid), (3) Relying on data analytics approaches that offer limited subsurface insight, and (4) Generating misleading results (e.g., on optimum fracturing method/fluid) through using disparate data that are unstructured and untrustworthy due to significant regional variation in true vertical depth (TVD), geological properties, fluid windows, completed lateral length, fracturing method/fluid/date, and drawdown rate management strategy. The present study eliminates these limitations by rigorously clustering the 4000+ Montney wells based on the TVD, geological properties, fluid window, completed lateral length, fracturing method/fluid/date, and drawdown strategy. This clustering technique allows for isolating the effect of each fracturing method by comparing each well's production (normalized by proppant tonnage, fluid volume, and completed length) to that of its offsets that use different fracturing methods but possess similar geology and fluid window. With similar TVD and fracturing fluid/date, wells completed with pinpoint fracturing outperform their offsets completed with ball and seat and plug and perf fracturing. However, wells completed with ball and seat and plug and perf methods that outperform their offset pinpoint wells have either: (1) Been fractured 1 to 4 years earlier than pinpoint wells and/or (2) Used energized oil-based fluid, hybrid fluid, and energized slickwater versus slickwater used in pinpoint offsets, suggesting that the water-phase trapping is more severe in these pinpoint wells due to the use of slickwater. Previous studies often favored one specific fracturing method or fluid without highlighting these complex interplays between the type of fracturing method/fluid, completion date (regional depletion), and the reservoir properties and hydrodynamics. This clustering technique shows how proper data structuring in disparate datasets containing thousands of wells with significant variations in geological properties, fluid windows, fracturing method/fluid, regional depletion, and drawdown strategy permits a consistent well performance comparison across a play by isolating the impact of any given parameter (e.g., fracturing methods, depletion) that is deemed more crucial to fracturing design and field development planning.

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Propogation LWD Tool Analysing for Better Saturation Estimation in High Angle Horizontal Well Conditions

10.2118/206624-ms ◽

2021 ◽

Author(s):

Airat Mingazov ◽

Andrey Zhidkov ◽

Marat Nukhaev

Keyword(s):

Horizontal Well ◽

Water Saturation ◽

Reservoir Properties ◽

Resistivity Measurements ◽

Well Completion ◽

Geological Conditions ◽

Formation Resistivity ◽

Time Propagation ◽

Resistivity Logging ◽

Logging Tool

Abstract Multidepth electromagnetic logging tool is considered as traditional measurements of formation resistivity estimation while drilling. When considering data in wells with high angles trajectory, more than 70 degrees, the resistivity measurements could be affected by several factors associated with geological conditions and logging tool specifications. As the result, during water saturation estimation formation properties could be distorted, which will lead to significant effect of reservoir properties assessment and the design of the horizontal well completion. Within the framework of this paper, various methods of influence on the resistivity readings will be considered, especially with cross boundary effects and reservoir formations with anisotropy. At the same time, propagation resistivity logging technologies while drilling with interpretation and boundary propagation technologies will be observed, which has tilted azimuthal oriented receivers for geosteering service of horizontal wells and additionally helps with take into account of boundary enflurane on standard resistivity logging.

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The coupled generation of organic acids and hydrocarbons during source rock maturation

10.5194/egusphere-egu2020-3402 ◽

2020 ◽

Author(s):

Jian Chen ◽

Jie Xu ◽

Zhenyu Sun ◽

Susu Wang ◽

Wanglu Jia ◽

...

Keyword(s):

Organic Acids ◽

Source Rock ◽

Maximum Yield ◽

Source Rocks ◽

Type I ◽

Hydrocarbon Generation ◽

Pore Waters ◽

Reservoir Properties ◽

Type Iii ◽

Short Period

Introduction: Organic acids which are commonly detected in oilfield waters, can partially enhance reservoir properties. Previous studies have suggested that cleavage of the oxygen-containing functional group in kerogen is a major source of organic acids. However, this cleavage is assumed to occur before the source rock enters the oil window. If this is correct, then these acids can dissolve only minerals in the source rocks. Presently, no detailed study of the generation of organic acids during the whole thermal maturation of source rocks has been conducted. It is unclear whether organic acids could migrate into reservoirs.Aim: This research simulated the thermal evolution of source rocks in order to build a coupled model of organic acid and hydrocarbon generation, and investigate if organic acids generated in source rocks can migrate into reservoirs.Methods: Three immature source rocks containing type I, II, and III kerogens were crushed to 200 mesh. These powders, along with deionized water, were sealed in Au tubes and heated to 220&#8211;360&#176;C for 72 h (EasyRo 0.37-1.16%). All the run products, including organic acids, gas, and bitumen, were analyzed.Results: At all temperatures, the organic acids dissolved in the waters are composed of formate, acetate, propionate, and oxalate. Acetate is the major compound with a modal proportion of >83%. The maximum yield of total organic acids was from source rocks containing type I kerogen (31.0 mg/g TOC), which was twice that from source rocks containing type II and III kerogens (13.3&#8211;15.4 mg/g TOC). However, for the type I and II kerogen-bearing source rocks, the organic acids reached a maximum yield (EasyRo = 1.16%) following the bitumen generation peak (EasyRo = 0.95%). Organic acids from type III kerogen-bearing source rocks reached their maximum yield (EasyRo = 0.95%) before the source rock entered the gas window (EasyRo > 1.16%).Conclusions: Our data suggest that the generation of organic acids is coupled with the generation of oil from type I and II kerogen-bearing source rocks, but form earlier than gas from type III kerogen-bearing source rocks. As such, some organic acids dissolved in pore waters are possibly expelled from source rocks containing type I and II kerogen with oils, which can then migrate into reservoirs. Migration of organic acids into reservoirs from source rocks containing type III kerogen is also possible in some situations. For example, when a source rock is rapidly buried for a short period, such as in the Kuqa Depression, Tarim Basin, China, the generation interval of organic acids and gas is short. Both could be expelled outside and migrate upwards into reservoirs. In conclusion, organic acids derived from source rocks can contribute to reservoir alteration.

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