GB/T 34163-2026Shale gas - Technical specification for the preparation of development plans (English PDF)

8.1 Description of basic conditions of the work area

8.1.1 Overview of the Work Area The work area overview description includes, but is not limited to, the following.

---Geographical location;

---Mining rights information;

---Overview of natural and social conditions related to the development and construction of the work area, and regional geological conditions.

8.1.2 Exploration Evaluation and Preliminary Work The description of the exploration assessment and preliminary work includes, but is not limited to, the following.

---Exploration evaluation and preliminary work process;

---Plan test or trial production status;

---Reserve declaration status.

8.1.3 Work Area Data Work area data includes, but is not limited to. seismic data, drilling data, well logging data, well logging data, coring data, fluid sampling data, experimental analysis data, segmented production testing data, and production data. Including dynamic monitoring data, etc. Data acquisition shall be carried out in accordance with GB/T 41613.

8.2 Gas reservoir description and reserve evaluation

8.2.1 Key Points of Gas Reservoir Description Based on static and dynamic data obtained from exploration and evaluation, pilot tests, trial production, and production capacity construction, gas reservoir description is carried out. Key points of gas reservoir description are attached. Record C.

8.2.2 Structural Features Describe the distribution, type, morphology, and characteristic parameters of the geological structures; describe the nature, distribution, and attitude of the faults. Follow the specifications in GB/T 39541. The compiled maps include, but are not limited to, structural plan views, seismic profile views, and target layer depth plan views.

8.2.3 Stratigraphic Characteristics Describe the stratigraphic position, depth, lithology, paleontology, thickness, top-to-bottom contact relationship, and well logging electrical and seismic properties by group, section, subsection, and small layer unit. Based on response characteristics, compile a comprehensive stratigraphic column. Conduct stratigraphic correlation analysis, finely subdivide sublayers, and compile stratigraphic thickness maps and stratigraphic correlation diagrams. Figure. Comply with GB/T 39541.

8.2.4 Characteristics of sedimentary facies Based on lithofacies and logging facies, the vertical and planar distribution characteristics of sedimentary facies, subfacies, and microfacies are described, and a comprehensive sedimentary facies column for a single well is compiled. Prepare a topographic map and a sedimentary facies plan to clearly identify areas with favorable sedimentary facies distribution. Follow the guidelines in GB/T 39541.

8.2.5 Reservoir Characteristics Describe the reservoir rock mineral characteristics, geochemical characteristics, pore structure characteristics, reservoir physical properties, gas content, and natural fracture development characteristics. Laminar characteristics, lateral reservoir distribution, and vertical interlayer stacking relationships. Comply with GB/T 39541.

8.2.6 Geomechanical characteristics Describe the characteristics of brittle minerals, rock mechanics, fracturability, geostress field characteristics, and geological body stability. According to GB/T 39541 The regulations shall be followed.

8.2.7 Gas reservoir types Describe formation temperature, formation temperature gradient, formation pressure, formation pressure coefficient, and fluid properties. The description method shall conform to GB/T 39541. Execution. Determine the gas reservoir type in accordance with NB/T 11335.

8.2.8 Geological Modeling Establish structural models, property models, geostress models, and natural fracture models in accordance with GB/T 39541 and NB/T 11043. The evaluation indicators for shale reservoir quality, drilling and completion performance, and reservoir stimulation adaptability are described in Appendix D. Models such as structural models, attribute models, geostress models, and natural fracture models are used for reserve calculation, reservoir stimulation simulation, gas reservoir numerical simulation, and production dynamic prediction. It provides support for the design of gas reservoir engineering schemes.

8.2.9 Production Dynamics Analyze the dynamic characteristics of gas well pressure, gas production, and fluid production, as well as formation flow characteristics; calculate the gas well pressure and gas production decline rate, and fracturing fluid return. Discharge rate and ultimate recoverable reserves (EUR) are used to evaluate the production capacity of gas wells. This should be carried out in accordance with NB/T 14015 and GB/T 41612.

8.2.10 Production Dynamics Forecasting It covers dynamic forecasting of pressure, production, and reserve utilization for individual wells, well groups, and development blocks, and establishes a system that includes analysis of production data. Statistical prediction models, dynamic prediction models based on well test analysis, and numerical simulation prediction models established based on geological modeling are used to predict biological phenomena. Production dynamics. The reliability of the model is verified using gas well production history, and model parameters are optimized and adjusted.

8.2.11 Gas Well Production Capacity Control Factors Analyze the impact of geological gas reservoir characteristics, drilling technology and parameters, well completion and reservoir stimulation technology and parameters, and production system on gas well productivity. Identify the controlling factors that affect high gas well production.

8.2.12 High-yield well model Establish high-yield well models by optimizing geological parameters, engineering process parameters, and reasonable gas well production systems.

8.2.13 Establishment of Standard Wells Based on the high-yield well model, and taking into account geological characteristics, engineering technology level, process parameters, and production system, the horizontal section length of the standard well is determined. Degree, first year production and EUR.

8.2.14 Development Zone Designation The scope of the development zone is determined by comprehensively considering the underground and surface conditions within the mining rights area. The basic conditions and details for determining the development zone are provided in Appendix E.

8.3 Gas Reservoir Engineering Scheme

8.3.1 Scheme Design Principles The geological reserves are highly utilized, the development technology and policies are scientific, the engineering technology is mature and applicable, and the health, safety, environmental protection and energy-saving measures are feasible. The development scale is large. The model and implementation arrangements are reasonable, and the overall technical and economic indicators are relatively good.

8.3.2 Development Layer Division The development strata are divided by comprehensively considering the geological and engineering characteristics of the reservoir, its vertical distribution, and the scope of vertical reservoir stimulation.

8.3.3 Development Unit Division Development is divided based on a comprehensive consideration of factors such as stratigraphic sequence, burial depth, structural features, reservoir characteristics, gas reservoir characteristics, preservation conditions, and fluid properties. The development unit is defined, and development technology policies, engineering processes, and parameters are formulated based on the geological and engineering characteristics of the development unit.

8.3.4 Mining Methods The depletion extraction method is recommended, while gas injection extraction can be considered for shale condensate gas reservoirs.

8.3.5 Development Methodology Cluster well development should be adopted. Stable production can be achieved through well area replacement, platform well group replacement, or single-well replacement.

8.3.6 Development Well Design For single-layer development, based on the structural characteristics, reservoir characteristics, and stress field characteristics of the development unit, combined with previous drilling, completion, and reservoir modification... To achieve the desired implementation effect, and taking into account the economic benefits of development, the design includes well type, well layout, target location, trajectory orientation, well spacing, and horizontal section length.

a) Well type. Optimize well type design by comprehensively considering factors such as geological and gas reservoir characteristics, engineering and technical conditions, gas well production capacity, and economic benefits.

b) Well placement method. Taking into account both underground and surface conditions, single-row or double-row well placement methods are adopted.

c) Target location. Based on the results of fine-grained sub-layer subdivision, and comprehensively considering fracture and micro-structural characteristics, reservoir quality, and engineering construction effectiveness, the target location is determined. Position the target.

d) Well trajectory orientation. In principle, perpendicular to the direction of the maximum horizontal principal stress. In areas with well-developed natural fractures, both the natural fractures and the stress direction should be considered. The orientation can be adjusted to match the angle between the well trajectory and the maximum horizontal principal stress.

e) Well spacing. The reasonable well spacing is determined by comprehensively considering factors such as well connectivity, single-well EUR and well-controlled geological reserve recovery rate.

f) Horizontal section length. Taking into account the development of micro-structures, reservoir depth, formation temperature, and combined with engineering and technical conditions, gas well EUR The length of the horizontal segment is determined by factors such as economic benefits. For multi-layer development, comprehensive consideration should be given to the results of development layer division, reservoir distribution characteristics, vertical inter-well interference, drilling, completion and reservoir modification. To ensure safety, a multi-layered well network was designed for development.

8.3.7 Well Location Deployment Design Taking into account factors such as the surface and underground conditions of the development zone and the feasibility of drilling projects, the optimal platform location was selected, and the number of deployable platforms and water levels were determined. Number of flat wells.

8.3.8 Gas Well Production Design Based on the production characteristics of gas wells, this study employs methods such as analogy, reservoir engineering, and numerical simulation, taking into account stress sensitivity, sand production, and critical fluid-carrying flow. Quantities, etc., are used to design gas well production systems and determine reasonable production allocation for gas wells. Dynamic production predictions are conducted throughout the entire lifecycle of typical wells of different types, and maps are created. Production output profile.

8.4 Drilling Engineering Plan

8.4.1 Basic Requirements for Drilling Engineering Design The main drilling technology should be mature and applicable, and the design of the wellbore trajectory and well structure should be able to ensure the realization of the geological and gas reservoir engineering plan. The geological objectives, casing and cementing designs are designed to meet the technical requirements of well completion, reservoir stimulation, and gas production projects for the wellbore. The design is safe, environmentally friendly, economical, and efficient.

8.4.2 Analysis of the Effects of Early Drilling Technology Conduct drilling process effectiveness analysis on pilot test wells or trial production wells implemented in the early stages, including but not limited to the following.

a) Drilling speed-up measures and their effects;

b) Geological steering measures and their effects in horizontal wells;

c) Casing and cementing quality analysis;

d) The status and effectiveness of prevention and control of downhole faults and complexities;

e) Safety and environmental protection measures and their effects.

8.4.3 Basic Data Required for Drilling Engineering Design The basic information required for drilling engineering design includes, but is not limited to, the following.

a) Regional basic geological data, including the basic structural characteristics, stratigraphic features, formation pressure coefficients, and mining subsidence of the target layer and overlying strata. The system includes information on the drilling area and oil and gas reservoirs, as well as risk warnings regarding potential complex drilling failures.

b) Well placement method and number of wells in cluster well groups;

c) Well spacing, target location, and horizontal section length;

d) Geological data acquisition requirements.

8.4.4 Main Design Contents of Drilling Engineering Drilling engineering design includes, but is not limited to, the following.

a) Surface well site design. Based on the well layout plan determined by the gas reservoir project, comprehensively consider the requirements of factory-style operation, safety and environmental protection requirements, and subsequent... The design of the surface well site shall take into account factors such as the needs of surface construction in the early stage, and the relevant requirements shall be implemented in accordance with the provisions of NB/T 14012.

8.5 Well Completion and Reservoir Stimulation Engineering Plan

8.5.1 Basic Requirements for Well Completion and Reservoir Stimulation Engineering Design With the aim of adapting to the geological and engineering conditions of the development zone and improving reservoir stimulation effects, advanced and mature well completion and reservoir stimulation technologies are adopted. Techniques include optimizing the main reservoir stimulation process, construction parameters, and wellbore materials; strengthening fracturing monitoring; and establishing a reasonable drainage and production system to ensure gas well production targets. The design scheme has been achieved.

8.5.2 Analysis of the Effectiveness of Early Well Completion and Reservoir Stimulation Techniques Analyze the completion and reservoir stimulation effects of pilot test wells or trial production wells implemented in the early stages, including but not limited to the following.

a) Status of well completion and reservoir stimulation implementation;

b) Compatibility evaluation of main technologies and parameters for well completion and reservoir stimulation;

c) Compatibility evaluation of key wellbore materials, including fluid systems, proppant types, and segmented tools;

d) The main factors affecting reservoir stimulation effects.

8.5.3 Design Contents of Well Completion and Reservoir Stimulation Projects Based on the evaluation of the reservoir stimulation effect in pilot test wells or production test wells, this approach aims to improve the complexity of artificial fractures and the generation of gas wells. The design of well completion and reservoir stimulation is carried out with the goal of improving production efficiency. The design of well completion and reservoir stimulation engineering includes, but is not limited to, the following.

a) Well completion design. The completed well depth should take into account the feasibility of reservoir stimulation equipment and processes. Casing should be run using a rotary casing method. Way.

b) Completion method. The completion method should take into account reservoir stimulation, implementation of drainage and gas production processes during the production phase, well workover operations, and safety production requirements. When performing casing completion, the casing selection should meet the construction displacement and segment tool type requirements of the reservoir stimulation design.

c) Perforation design. The design includes the spacing, density, and phase angle of the perforation clusters in the horizontal section, as well as the type of perforation cartridge; in the selected oil layer In the case of casing, the perforation parameters should be designed based on the reservoir stimulation effect of the pilot test well or production test well and the requirements of volumetric fracturing technology.

d) Wellhead equipment. Factors such as fluid properties, maximum shut-in pressure, wellhead temperature, average annual air temperature, and maximum gas flow rate should be comprehensively considered. Select the materials, pressure and temperature ratings, and sealing connection methods for the wellhead equipment; for high-temperature, high-pressure, and high-yield gas wells, improve the well... Requirements for pressure and temperature monitoring devices for inlet devices.

e) Reservoir stimulation technology. It should be based on the fracturing effect of the pilot test well or production test well, combined with the wellbore structure, well depth, and oil layer. Based on casing parameters and reservoir geological and engineering characteristics, the main process is determined.

f) Reservoir stimulation parameters. including segment design, perforation location, drilling displacement, sand injection intensity, and fluid usage intensity, etc. Segment design... The design should take into account factors such as reservoir properties, structure, distribution of natural fractures, dogleg degree, and formation fracture pressure when the well trajectory traverses the sub-layers. The geological and engineering parameters of the first-stage modification section should be basically consistent to ensure uniform modification under multi-cluster conditions; the perforation location should avoid high doglegs and faults. Unfavorable factors, based on the evaluation results of fracturing construction parameters of pilot test wells or production test wells, and comprehensively considering geological and engineering characteristics, Downhole complexity includes risks such as casing deformation and pressure channeling, requiring specific design and construction parameters.

g) Key materials used in wellbore operations. including fracturing fluid system, proppant type, and staged stimulation tools. A comprehensive consideration of the reservoir rock and mineral composition is recommended. Based on the composition, brittle mineral content, and reservoir rock mechanical characteristics, combined with the evaluation of the fracturing fluid system in pilot test wells or production wells, the following factors are considered. The fracturing fluid system was optimized based on the principles of low damage, low cost, and facilitating the formation of complex artificial fractures. The properties of slickwater were considered according to... The crosslinking liquid performance shall comply with the provisions of NB/T 14003.1, and the performance of the crosslinking liquid shall comply with the provisions of NB/T 14003.3; combined with pilot test wells or tests The evaluation results of well proppant effectiveness were based on a comprehensive assessment of reservoir closure pressure, artificial fracture opening width, and laboratory experimental results. Economic considerations should be taken into account when determining the type and dosage of proppant; the performance of the proppant should comply with the requirements of SY/T 5108; the oil layer casing should be comprehensively considered. The optimal segmentation should be selected based on the model, fracturing process, and horizontal wellbore conditions, ensuring effective separation of each modified section and gas well production. tool.

8.6 Gas Production Engineering Scheme

8.6.1 Basic Requirements for Gas Production Engineering Design Based on the gas reservoir engineering design, fully utilize formation energy, and adopt mature, applicable, safe, reliable, and economically feasible gas production technologies. This technology ensures safe and stable production of gas wells and improves production management.

8.6.2 Analysis of the Effectiveness of Preliminary Gas Production Technology Analyze the gas production process effectiveness of pilot test wells or trial production wells implemented in the early stages, including but not limited to the following.

a) Adaptability of tubing size;

b) Drainage gas extraction technology and its effects;

c) Measures and effects of hydrate control;

d) Oil pipe corrosion protection process and effect.

8.6.3 Gas Production Engineering Design Contents The design scope of gas production engineering includes, but is not limited to, the following.

a) Production tubing design. Production tubing design should be carried out based on the gas well production and well condition requirements, including optimal tubing size and structural design. Strength verification, timing of insertion, and depth design;

b) Downhole corrosion and anti-corrosion technology. It is advisable to comprehensively consider the corrosion environment, corrosion factors, corrosion rate, and corrosion degree of wells put into production in the early stage. Based on the results of the assessment, anti-corrosion measures were formulated.

c) Drainage and Gas Production Technology. The optimal technology should be selected by comprehensively considering factors such as the dynamic prediction of gas well production throughout its entire life cycle, well structure, and surface infrastructure. Drainage-based gas extraction technology or combination of technologies;

d) Dynamic monitoring. The dynamic monitoring technology should be selected based on the dynamic monitoring content defined in the gas reservoir project.

e) Information technology in gas production processes. The design of gas production equipment, site design, and gas production process should consider the automation and production data of gas wells. The application of information technology can improve the technical level of gas well production management.