Application of 3D Geomechanical Research for De-Risk and Improve High Pressure and High Temperature Well Drilling

2021 ◽  
Author(s):  
Ming Yi ◽  
Ling Liu ◽  
Qiang Wei ◽  
Liang Chen ◽  
Binging Li ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Energy Demand ◽  
Integrated Approach ◽  
Earth Model ◽  
Stress Profile ◽  
Drilling Process ◽  
Geomechanical Model ◽  
Wellbore Instability ◽  
3D Geomechanical Model

Abstract Exploration focus is moving into deeper targets of high pressure and high temperature (HPHT) regime due to the ever-increasing energy demand of China. Overpressure and wellbore instability related problems in such setting are mainly associated with narrow drilling margin resulting in severe well control incidents and increased drilling cost. In order to reduce drilling risks and operation costs, an accurate geomechanical model is necessary. The model provides technical support for drilling process and minimum reservoir damage due to optimal mud weight program. Well-scale (1D) Mechanical Earth Model (MEM) is constructed on the offset wells which consist of rock strength properties and stress profile by incorporating all available data including open hole log data, geomechanical core lab results, LOT/FIT, direct pore pressure measurements and drilling events. Furthermore, 3D geomechanics model is generated using available well-scale MEM data in the field and distributed throughout the field which guided by seismic interpretation data as distribution control. The 3D geomechanical model is used to design mud weight and casing program for the upcoming well. The offset wells in the study areas were drilled through complex geological settings with high overpressure (13500 psi) and high temperature (200-220 deg C). Therefore, drilling operations is also risky with different types of drilling events encountered frequently including stuck pipe, inflow, losses and connection gas etc. With 3D geomechanical model as the foundation, the integrated approach helps ultra-deep wells to reduce serious wellbore instability caused by abnormal formation pressure, wellbore collapse and other complex drilling problems. The implementation of systematic and holistic workflow has proven to be extremely successful in supporting the drilling of HPHT wells in China. The integrated solution has been applied in the ultra-deep well, recorded an improvement in ROP by 35.3% and decrease no-productive time (NPT) by 25.3% compared with offset well. The geomechanical approach provides a convenient means to assist field engineers in the optimization of mud weight, risk assessment, and evaluation of HPHT wells drilling performance. The findings will provide reference and guideline for de-risk and performance improvement in HPHT wells drilling.

Design Challenge of Rigid Riser-Spool Piece Against HTHP Induced Expansion in Pipe-in-Pipe Systems

2014 ◽  
Author(s):  
Facheng Wang ◽  
Ming Gao ◽  
Jun Wang ◽  
Yigong Zhang ◽  
Xu Jia ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Energy Demand ◽  
Bohai Sea ◽  
Oil And Gas ◽  
Mainland China ◽  
Structural Complexity ◽  
Calculation Model ◽  
Fluid Temperature ◽  
Gas Reservoirs

Developments of oil and gas reservoirs in Bohai Sea, South China Sea etc., are presently accelerated, to cope with the significant increase in energy demand from the mainland, China. In recent developments in Bohai Sea, fluid temperature and pressure have been found dramatically being increased up to 100 °C and 20 MPa respectively. The fact that High Temperature and High Pressure (HTHP) in Bohai area brings design challenges, especially to jacket risers and spool pieces. Pipe-in-Pipe (PIP) flowline systems have been widely employed in this region and are continuously being considered for further developments. This is due to its significant thermal insulation capacity to deal with the High Temperature and High Pressure (HTHP) issue. To cope with the challenges induced by HPHT and structural complexity of PIP, COTEC Offshore Engineering Solutions, together with its mother company, China Offshore Oil Engineering Company, have developed a approach by using ABAQUS and AutoPIPE. This paper describes the relevant experience obtained during one development in Bohai Sea, BZ34-2/4 project containing dozens of risers and spool pieces. Two main parts are presented. Firstly, a beam-element based expansion calculation model adopting ABAQUS has been developed to achieve accurate HPHT induced expansions. The structural behavior of PIP can be represented in the developed model, meanwhile with minimum increase in modeling complexity. Secondly, practical and extensive parametric studies have been carried on the riser and spool flexibility against HPHT induced expansions. Since Bohai Sea has been developed extensively, many risers are post-installed and the existing of restriction areas practically enlarges the difficulties of anchor clamp and spool arrangements. Key parameters of these arrangements, such as Z/L shape, the length between two bends, the combinations of bend angles, the length of protection pipe on the riser etc. have been comprehensively investigated. “Gold” rules for rigid riser accessories arrangements and spool piece layout have been suggested accordingly.

scholarly journals Building 1D Mechanical Earth Model for Zubair Oilfield in Iraq

2020 ◽  
Vol 26 (5) ◽  
pp. 47-63
Author(s):  
Aows Khalid Neeamy ◽  
Nada Sabah Selman
Keyword(s):  
Earth Model ◽  
Drilling Process ◽  
Suitable Alternative ◽  
Wellbore Instability ◽  
Drilling Operations ◽  
Mechanical Earth Model ◽  
Alternative Solutions ◽  
Drilling Time ◽  
Productive Time ◽  
Critical Limits

Many problems were encountered during the drilling operations in Zubair oilfield. Stuckpipe, wellbore instability, breakouts and washouts, which increased the critical limits problems, were observed in many wells in this field, therefore an extra non-productive time added to the total drilling time, which will lead to an extra cost spent. A 1D Mechanical Earth Model (1D MEM) was built to suggest many solutions to such types of problems. An overpressured zone is noticed and an alternative mud weigh window is predicted depending on the results of the 1D MEM. Results of this study are diagnosed and wellbore instability problems are predicted in an efficient way using the 1D MEM. Suitable alternative solutions are presented ahead to the drilling process commences in the future operations.

Analysis of Wellbore Instability in an Offshore Field: A Case Study

2018 ◽  
Author(s):  
Nubia Aurora González Molano ◽  
José Alvarellos Iglesias ◽  
Pablo Enrique Vargas Mendoza ◽  
M. R. Lakshmikantha
Keyword(s):  
Field Effect ◽  
Point Of View ◽  
Wellbore Stability ◽  
Geomechanical Model ◽  
Wellbore Instability ◽  
3D Geomechanical Model ◽  
Shale Formation ◽  
Major Factors ◽  
Offshore Field

Several wellbore instability problems have been encountered during drilling a shale formation in an offshore field, leading to the collapse of the main borehole and resulting in several sidetracks. In this study, an integrated 1D & 3D Geomechanical model was built for the field in order to investigate the major factors that control the instability problems from a Geomechanical point of view and to design an optimum mud window for planned wells in the field. Effect of bedding on wellbore stability was the most important factor to explain the observed drilling events. Optimized well paths for planned wells were proposed based on results of a sensitivity analysis of the effect of bedding orientation on wellbore stability. It has been observed that bedding exposed depends not only on well inclination but also on dip of the formation, attack angle, and azimuth.

Integrated Experimental and Analytical Wellbore Strengthening Solutions by Mud Plastering Effects

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Saeed Salehi ◽  
Raj Kiran
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Drilling Fluid ◽  
Wellbore Stability ◽  
Stress Profile ◽  
Laboratory Studies ◽  
Mud Cake ◽  
Stress Changes ◽  
Wellbore Strengthening ◽  
The Impact

Wellbore stability has plagued oil industry for decades. Inclusion of the mud in drilling and the effect of mud cake build up incorporate very complex chemical, thermal, mechanical, and physical phenomena. It is very difficult to quantify all these phenomena in one model. The after effects of mud cake buildup, its permeability and variation in thickness with time alter the actual stress profile of the formation. To see the impact of the whole mechanism, a combination of laboratory studies and numerical modeling is needed. This paper includes the procedure and results on stress profiles in near wellbore region based on laboratory studies of mud cake buildup in high pressure and high temperature environment using permeability plug apparatus (PPA). The damaged formation zone is very susceptible to drilling fluid and results in alteration of existing pore pressure and fracture pressure. This paper presents integrated experimental and analytical solutions for wellbore strengthening due to mud cake plastering. Conducting experiments on rock core disks has provided more realistic results which can resemble to field conditions. The experimental work here provides an insight to effect of mud cake build up at high pressure and high temperature conditions using a heterogeneous filtration medium prepared from different sandstone cores. Results were used in the analytical model to see the effect of stresses in the formation. The primary objective is to investigate the wellbore hoop stress changes due to formation of filter cake by mud plastering using the analytical models built upon the laboratory results. The models developed in this work provide insights to quantify on wellbore plastering effects by mud cake build up.

Innovative Drilling Fluid Technology Conquered Tough Geomechanics Offshore Mexico

2021 ◽  
Author(s):  
Ricardo Reyna ◽  
Viridiana Parra ◽  
Daniel Volbre ◽  
Raul Ballinas ◽  
Reinaldo Maldonado ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Best Practices ◽  
Drilling Fluid ◽  
Cost Savings ◽  
Lessons Learned ◽  
New Production ◽  
Wellbore Instability ◽  
High Pressure High Temperature ◽  
Intermediate Section

Abstract The reservoir field highlighted in this paper is located Offshore Mexico in the southeast part of Campeche Bay and hidden below a troublesome, unstable formation that must be transacted before reaching the new production zone. During the exploration phase, this section experienced severe lost circulation and unstable conditions before reaching the final depth. Based on lessons learned, the team worked to develop a best- practices approach using geomechanics analysis and a novel fluid technology which enabled the operator to safely drill through this problematic intermediate section under high-pressure, high-temperature (HPHT) conditions. The methodology started with identifying the geomechanics challenges, implementing operational best practices, and finally, use of an innovative, low-invasion fluid technology, which creates a thin and impermeable shield at the wellbore wall, effectively sealing the fractures and preventing fracture propagation in the highly unstable formation of interspersed carbonates, shales, and sandstones. The strong mechanical properties of the thin, but firm, barrier created at the wellbore wall minimized the destabilizing effect of fluid invasion. Synergy from the geomechanical team, best practices for the operation, and innovative drilling fluid technology solved the wellbore instability drilling challenge encountered in the exploration well. In offset wells, losses of more than 2,200 m3 of drilling fluid, stuck pipe, and major NPT were observed. By incorporating the shielding technology, wellbore instability was improved in the intermediate section. In addition, the fluid technology was easily pumped through the bottomhole assembly (BHA) to seal formation fractures between 2,000 and 3,000 μm in size. This well, utilizing the barrier technology to mitigate the wellbore instability and drill within a narrow fracture gradient operating window, was the first in the area to have zero loss of drilling fluid as compared to the typical 5 to 10-m3/hr circulation losses experienced during exploration drilling in the intermediate section characterized by interbedded layers of carbonates, shales, and sandstone under high-pressure, high-temperature (HPHT) conditions. The coordination between the teams using best practices was critical to meeting the challenge of the intermediate geomechanically weak formation. This case history in offshore Mexico will demonstrate both the importance of teamwork and the utilization of a proven technology that improves wellbore instability, minimizes NPT, mitigates pipe tripping issues and avoids huge volumes of drilling fluid lost into the geomechanically weak formation. This barrier technology can be applied globally to troublesome formations - such as interbedded carbonates, shales, and sandstones - to improve operations and provide cost savings for the operator.

scholarly journals Geomechanical modelling and two-way coupling simulation for carbonate gas reservoir

2020 ◽  
Vol 10 (8) ◽  
pp. 3619-3648
Author(s):  
Barzan I. Ahmed ◽  
Mohammed S. Al-Jawad
Keyword(s):  
Fluid Flow ◽  
Slip Flow ◽  
Gas Production ◽  
Natural Fracture ◽  
Rock Properties ◽  
Earth Model ◽  
Geomechanical Model ◽  
Gas Reservoir ◽  
Permeability Model ◽  
3D Geomechanical Model

Abstract Geomechanical modelling and simulation are introduced to accurately determine the combined effects of hydrocarbon production and changes in rock properties due to geomechanical effects. The reservoir geomechanical model is concerned with stress-related issues and rock failure in compression, shear, and tension induced by reservoir pore pressure changes due to reservoir depletion. In this paper, a rock mechanical model is constructed in geomechanical mode, and reservoir geomechanics simulations are run for a carbonate gas reservoir. The study begins with assessment of the data, construction of 1D rock mechanical models along the well trajectory, the generation of a 3D mechanical earth model, and running a 4D geomechanical simulation using a two-way coupling simulation method, followed by results analysis. A dual porosity/permeability model is coupled with a 3D geomechanical model, and iterative two-way coupling simulation is performed to understand the changes in effective stress dynamics with the decrease in reservoir pressure due to production, and therefore to identify the changes in dual-continuum media conductivity to fluid flow and field ultimate recovery. The results of analysis show an observed effect on reservoir flow behaviour of a 4% decrease in gas ultimate recovery and considerable changes in matrix contribution and fracture properties, with the geomechanical effects on the matrix visibly decreasing the gas production potential, and the effect on the natural fracture contribution is limited on gas inflow. Generally, this could be due to slip flow of gas at the media walls of micro-extension fractures, and the flow contribution and fracture conductivity is quite sufficient for the volume that the matrixes feed the fractures. Also, the geomechanical simulation results show the stability of existing faults, emphasizing that the loading on the fault is too low to induce fault slip to create fracturing, and enhanced permeability provides efficient conduit for reservoir fluid flow in reservoirs characterized by natural fractures.

Microstructural Study of Diamond Deformed Under High Pressure and Temperature

1985 ◽  
Vol 43 ◽  
pp. 230-231
Author(s):  
E. F. Koch
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Lattice Structure ◽  
Diamond Particle ◽  
Polycrystalline Diamond ◽  
Sintering Process ◽  
Ion Milling ◽  
Sintered Compact ◽  
Transmission Electron ◽  
High Pressure Sintering

Because of the extremely rigid lattice structure of diamond, generating new dislocations or moving existing dislocations in diamond by applying mechanical stress at ambient temperature is very difficult. Analysis of portions of diamonds deformed under bending stress at elevated temperature has shown that diamond deforms plastically under suitable conditions and that its primary slip systems are on the ﹛111﹜ planes. Plastic deformation in diamond is more commonly observed during the high temperature - high pressure sintering process used to make diamond compacts. The pressure and temperature conditions in the sintering presses are sufficiently high that many diamond grains in the sintered compact show deformed microtructures.In this report commercially available polycrystalline diamond discs for rock cutting applications were analyzed to study the deformation substructures in the diamond grains using transmission electron microscopy. An individual diamond particle can be plastically deformed in a high pressure apparatus at high temperature, but it is nearly impossible to prepare such a particle for TEM observation, since any medium in which the diamond is mounted wears away faster than the diamond during ion milling and the diamond is lost.

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