Real-Time Down-Hole Monitoring of Gas Injection Profile Using Fibre-Optic Distribute Temperature and Acoustic Sensing in Tarim

2021 ◽  
Author(s):  
Defei Chen ◽  
Kun Huang ◽  
Xiangjuan Meng ◽  
Ju Liu ◽  
Bao Zhang ◽  
...  
Keyword(s):  
High Temperature ◽  
Real Time ◽  
Oil Recovery ◽  
Fiber Optic ◽  
Gas Injection ◽  
Injection Well ◽  
Fibre Optic ◽  
Distributed Temperature Sensing ◽  
Acoustic Sensing ◽  
Gas Channeling

Abstract Gas injection has become an important means of enhancing oil recovery (EOR) in clastic reservoirs, the Donghe Oilfield, Tarim, has been undergoing gas injection to enhanced oil recovery. During the gas injection, dynamic justification of gas injection was the most severe challenges, which needed to monitor the pressure profile, temperature profile and gas injection profile. Therefore, monitoring gas injection profile has becoming an important part of gas drive reservoirs. Donghe Oilfield was characterized by ultra-deep (>6000m), high temperature (>140°C) and high content of carbon dioxide, conventional manometer and thermometer cannot meet the downhole condition of ultra-deep and high temperature. To continuously monitor gas injection well, permanent fibre-optic surveillance technique featured with outstanding conformance, nice corrosion resistance and long-life span was developed, and a program was developed to use real-time fiber-optic Distributed Temperature Sensing (DTS) and Distributed Acoustic sensing (DAS) to identify the gas injection profile (gas channeling). Monitoring principle and system assembly of the fibre-optic was demonstrated in detail, the DTS utilized Joule - Thompson cooling principle as the gas injected into formation through screen pipe, while the DAS captured the amplitude and frequency of acoustics from the gas flow. DTS and DAS data obtained at the same time by using fiber wireline outside the gas injection string during gas injection. There was a field application in gas injection well of DH1-H3 and gas injection profiles derived from DTS and DAS had the extremely high consistency to radioactive tracer profiles run at about the same time and under similar injection rates and pressure. The success of the fibre-optic surveillance in DH1-H3 exhibited great potential of fiber-optic sensing in gas injection EOR projects, which could provide a new and effective tool in identifying gas channeling.

The Application of the Multi-Component Thermal Fluid Huff and Puff Technology to Daqing Heavy Oil Block

2021 ◽  
Author(s):  
Xianjun Wang ◽  
Xiangbin Liu ◽  
Borui Li ◽  
Qiang Yin ◽  
Zhonglian Han ◽  
...  
Keyword(s):  
High Temperature ◽  
Corrosion Inhibitor ◽  
Oil Recovery ◽  
Heavy Oil ◽  
Thermal Recovery ◽  
Gas Absorption ◽  
Composition Ratio ◽  
Steam Flooding ◽  
Gas Channeling ◽  
Lock In

Abstract The reservoir of Daqing Heidimiao Oilfield (permeability 1736×10−3μm2) contains heavy oil, with the average viscosity of 3306 mPa•s. It is developed by steam flooding and steam huff and puff, however, the recovery rate is only 14.6%. Therefore, the multi-component thermal fluid huff-and-puff technology is applied to, dealing with pertinent problems such as gas channeling, corrosion and oil pump lock in the process so as to improve oil recovery and production. Mechanism: Cooling by water, the ultra-high temperature gas generated via combustion of diesel or natural gas with air produces a multi-component thermal fluid containing CO2,N2 and vapor, combining the advantages of gas absorption and thermal recovery. Simulation: A multi-component and multi-phase percolation model is built to optimize the huff-and-puff parameters including composition ratio, temperature and injection volume. Supporting techniques: a high temperature oil-and-acid resistant foam system to form a precedent-blocking slug and automatically adjust the huff-and-puff profile. a dedicated low-cost and high-efficiency corrosion inhibitor system to realize corrosion-resistance. a four-node down-hole gas-liquid separation device to increase efficiency. The comprehensive reduced-viscosity rate is more than 30%; high-pressure air chambers, ranging from 0.2 to 2.0MPa, are formed for elastic energy replenishment. Field tests show the average annual oil increase per well is about 3800 barrels, with the highest being about 7200 barrels. The numerical simulation results show that the optimal composition ratio (N2: CO2: vapor) is 5:1:1.5, that the best injection amount is 30∼50×104Nm3 and that the injection temperature is preferably 280 ∼ 300 °C. The oil-and-acid resistant foaming agent has improved recovery efficiency, as a significantly improved profile of gas absorption, and the oil extraction degree increases by about 31.5%. High temperature corrosion is prevented, through intermittent injection of high-temperature-resistant corrosion inhibitor (corrosion inhibition rate 70.5% at 350 °C), and the frequency of pipeline corrosion is reduced averagely by 98.5%. Air-lock in pump vanishes via gas-liquid separation devise, with the average indoor pump efficiency increases by more than 50% (gas-liquid ratio ≤3000m3/m3)and the one in field test increases from less than 20% to over 45%. More importantly, the maintenance period has reached 662d. This technology has been applied to 98 wells in Daqing to date, 95 of which are stimulated successfully. The multi-component thermal fluid huff-and-puff technology solves the problems such as gas channeling, corrosion and air-lock in pumps through supporting techniques and the synergism of steam flooding and thermal recovery to enhance oil recovery and can be used as a superseded technology after steam huff-and-puff treatment to increase the EUR, especially for heavy oil reservoirs with medium and high permeability.

Challenges, Requirements and Advances for Distributed Fiber Optic Sensors in SURF Structures and Subsea Well Monitoring

2013 ◽  
Author(s):  
Fabien Ravet ◽  
Etienne Rochat ◽  
Marc Niklès
Keyword(s):  
Oil Recovery ◽  
Fiber Optic ◽  
Dead Zone ◽  
Oil And Gas Industry ◽  
Hotspot Detection ◽  
Distributed Temperature Sensing ◽  
Offshore Structure ◽  
Integrity Monitoring ◽  
Minimum Requirement ◽  
Common Mean

During the past 10 years, the oil and gas industry has gained confidence in the capabilities and the reliability of Fiber Optic Distributed Sensing (OFDS). Real world implementation can be found in both downstream and upstream branches. For example, at one end of the industry spectrum, service companies have started to use Distributed Temperature Sensing (DTS) for in-well temperature monitoring to optimize oil recovery processes. At the other end, pipeline operators have installed pipeline integrity monitoring systems based on Distributed Temperature and Strain sensing (DITEST) to fulfill realtime monitoring of soil stability, pipeline 3D deformation and leak detection. The use of OFDS for offshore structure integrity monitoring such as flow lines, risers and umbilicals has been qualified and field tested already whereas other applications such as performance rating of power umbilicals and enhanced flow assurance system using OFDS are being evaluated. Currently, the offshore full scale implementation of OFDS technologies still faces challenges of its own. In particular, sensor integration into the structure to be monitored is a minimum requirement which applies to any OFDS. If fiber optic is a common mean of data transmission, subsea conditions imply the use of specific components such as Wet Mate Connectors (WMC) and Fiber Optic Rotary Joints (FORJ). These components present large insertion and return loss characteristics for which OFDS require special attention to the OFDS system to comply with such characteristics. The effect of these components is twofold. First it impacts the sensor optical budget limiting its measurement range. Second, sensor sections remain completely blind due to the high reflection levels leaving the structure without status information over distances that can be as large as several kilometers. The present works describes how the DITEST based on Stimulated Brillouin Scattering (SBS) can overcome the limitations imposed by both WMC and FORJ components and fully comply with SURF monitoring requirements. The ability of the DITEST is justified theoretically and demonstrated experimentally through qualification trials involving hotspot detection while WMC and FORJ are part of the sensor path. Their effects are quantified through the determination of the measurement dead zone (shorter than 4m), the temperature uncertainty and the resolution. The work also reports the subsequent installation on operational structures as these trials were successful. The DITEST has been installed to continuously monitor the temperature of a 3km long power umbilical and control the heating system of subsea rigid flowlines whose length can be as large a 45km.

Fiber Optic DTS and DAS as an Alternative Interpreted Intelligent Completions Extended Abstract

2021 ◽  
Author(s):  
Nur'ain Minggu ◽  
Latief Riyanto ◽  
Chang Siong Ting ◽  
Dahlila Kamat ◽  
Dylan Zhe Ho ◽  
...  
Keyword(s):  
Fiber Optic ◽  
Production Optimization ◽  
Operating Conditions ◽  
Temperature Sensing ◽  
Position Tracking ◽  
Distributed Temperature Sensing ◽  
Acoustic Sensing ◽  
Valve Position ◽  
Valve Opening ◽  
Distributed Acoustic Sensing

Abstract This study aims to validate and track valve positions for all the zones applying recorded Distributed temperature sensing (DTS) and Distributed acoustic sensing (DAS) data interpretation in order to propose the best combination of downhole inflow control valve (ICV) openings, This is required to optimize Well X-2 multizone commingled production. Fiber DTS and DAS monitoring were relied on as an innovation against downhole conditions that has compromised the three out of four downhole dual-gauges and valve position sensors. For zonal water control purpose, ICV cycling and positioning have been attempted in 2019. The valve position tracking derived from the compromised downhole dual gauges and valve position sensors does not tally with the surface flow indication overall. Consequently, the original measurement intention of the permanently installed distributed fiber-optic which served as back-up zonal-rate calculation profiling and as potential sub-layer flow-contribution indicators is brought in as contingency zonal valve-opening tracking and guides that proved valuable for subsequent production optimization. First part of study involves interpretation of Distributed Temperature Sensing (DTS) data. Downloaded DTS data is depth matched and validated against known operating conditions like time of each cycling stage and surface well test parameters (i.e. Liquid Rate, Watercut, Tubing Head Pressure (THP), Total Gas, Gas-Oil Ratio (GOR)), etc. To establish a baseline, several DTS traces of historical operating condition during a known stable period were selected, i.e. stable flowing condition at only Zone 4 stable shut-in condition at surface with only ICV Zone 4 is opened Downhole valve-position tracking can be interpreted alternatively from induced fiber temperature activities across the valve depth with a good temperature baseline benchmarking from DTS temperature profiling. Second part of study involves interpretation of Distributed Acoustic Sensing (DAS) data. The data was acquired under single flowing condition one month post-ICV cycling. Without any changes made on the well operating conditions, the well is flowing under same condition post ICV cycling. Inflow point detection using joint interpretation of DAS and DTS, where simultaneously DAS spectral content (depth-frequency) was analysed alongside DTS traces to further discriminate between inflow and other noise sources. Through i) acoustic amplitude analysis, ii) DTS inversion, iii) noise speed and flow speed computation, composite production allocation can be derived for Well X-2. Using the alternative co-interpretations based on fiber temperature and acoustic measurement, it is found and validated that Zone 1 ICV is Closed, Zone 2, 3 and 4 are in opened position and continuously producing at any cycles. This is in conflict of zonal production control understanding initially based on the compromised downhole sensors indicating that all the zonal valves are supposedly in fully closed position. In this case-study, DTS and DAS data has been proven useful and as an innovative, alternative monitoring to determine downhole valve opening with analogue to flow contribution derivation methodology. Therefore, anytime in the future where Well X-2 valves cycling is planned to be carried out, there is now a corresponding operating procedure that is incorporated onsite real-time fiber optic DTS and/or DAS data monitoring to validate tracked valves positioning.

scholarly journals Numerical Simulation via CFD Methods of Nitrogen Flooding in Carbonate Fractured-Vuggy Reservoirs

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7554
Author(s):  
Kexing Li ◽  
Bowen Chen ◽  
Wanfen Pu ◽  
Jianhai Wang ◽  
Yongliang Liu ◽  
...  
Keyword(s):  
Conceptual Model ◽  
Oil Recovery ◽  
High Speed ◽  
Physical Simulation ◽  
Fluid Dynamic ◽  
Gas Injection ◽  
Water Flooding ◽  
Injection Mode ◽  
Well Pattern ◽  
Gas Channeling

A reservoir-scale numerical conceptual model was established according to the actual geological characteristics of a carbonate fractured-vuggy reservoir. Considering the difference in density and viscosity of fluids under reservoir conditions, CFD (computational fluid dynamic) porous medium model was applied to simulate the process of nitrogen displacement in a fractured-vuggy reservoir after water flooding. The effects of gas injection rate, injection mode, and injector–producer location relation were studied. The results show that nitrogen flooding can yield additional oil recovery of 7–15% after water flooding. Low-speed nitrogen injection is beneficial in obtaining higher oil recovery. High speed injection can expand the sweep area, but gas channeling occurs more easily. In gas–water mixed injection mode, there is fluid disturbance in the reservoir. The gas channeling is faster in low injector–high producer mode, while the high injector–low producer mode is beneficial for increasing the gas sweep range. Nevertheless, the increment of recovery is closely related to well pattern. After nitrogen flooding, there are still a lot of remaining oil distributed in the trap area of gas cap and bottom water in the reservoir that water and gas injection can’t sweep. The establishment of the numerical conceptual model compensates for the deficiency of physical simulation research, stating that only limited parameters can be simulated during experiments, and provides theoretical bases for nitrogen flooding in fractured-vuggy reservoir.

Field Pilot Test of Micro-Dispersed Gel Foam in Fractured-Vuggy Carbonate Reservoirs

2021 ◽  
Author(s):  
Yuchen Wen ◽  
Jirui Hou ◽  
Ming Qu ◽  
Weipeng Wu ◽  
Tuo Liang ◽  
...  
Keyword(s):  
Gas Injection ◽  
Carbonate Reservoir ◽  
Production Performance ◽  
Injection Well ◽  
Pilot Test ◽  
Nitrogen Gas ◽  
Before And After ◽  
Production Wells ◽  
Gas Flooding ◽  
Gas Channeling

Abstract This paper summarizes the change rule of production performance and the EOR efficiency from the micro-dispersed gel foam injection in the fractured-vuggy carbonate reservoir of Tahe Oilfield. The TK722CH2 well group injected gas from August 2014 to September 2018. During the gas injection stage, the effect of periodic gas injection decreased obviously, the effective direction of gas injection was single and the risk of gas channeling increased greatly. The field pilot test f micro-dispersed gel foam was carried out on September 20, 2018. The fluid is injected into well group in three slugs: micro-dispersed gel foam, normal foam and nitrogen gas. As a part of the foam pilot test monitoring, a gas tracer study was performed before and after the injection of gel foam in the reservoir. After the pilot test was carried out in the TK722CH2 well group, the subsequent injection gas swept new fractures and vugs, and a new dynamic connectivity has been established. The connectivity of well group changed from 1 injection well connects with 1 production well to 1 injection well connects with 4 production wells. Through the field pilot test of micro-dispersed gel foam, this paper verifies the effect of improve gas flooding and increase sweep volume of micro-dispersed gel foam. By analyzing the results of the field pilot test, the relevant technical mechanism of micro-dispersed gel foam in fractured-vuggy reservoir is revealed. As a result, the field pilot test in this paper provides theoretical basis and technical support for the efficient development of fractured-vuggy carbonate reservoir.

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