The high temperatures existing within a geothermal well preclude the use of most logging instrumentation which is necessary to study the wellbore and surrounding rock matrix. Possible solutions to this problem include cooling the wellbore and the surrounding rock by circulating fluid in the wellbore and by injecting fluid directly into the rock matrix. The latter method, however, is not preferr...

The relationship between production rates of large diameter geothermal production wells, and slimholes, is studied. The analysis is based on wells completed in liquid-dominated geothermal fields, where flashing occurs either in the wellbore or at the surface. Effects of drawdown in the reservoir, and pressure drop in the wellbore, are included; heat losses from the wellbore to the formation are...

Horizontal wells can significantly improve the gas production and are expected to be an efficient exploitation method for industrialization of natural hydrates (NGHs) in future. However, near-wellbore hydrate is highly prone decomposition during drilling process, owing disturbance aroused by factors such as fluid temperature, pressure, salinity. These issues result engineering accidents bit sti...

Most salt rock has interbed of mudstone in China. Owing to the enormous difference of mechanical properties between the mudstone interbed and salt rock, the stress-strain and creep behaviors of salt rock are significantly influenced by neighboring mudstone interbed. In order to identify the rules of wellbore shrinkage and casings equivalent stress in bedded salt rock stratum, three-dimensional ...

Abstract Wellbore instability causes main concerns in the oil and gas industry due to personnel safety overall expenditure. Several signs such as wellbore spalling, rate of penetration reduction, pipes sticking, well unnatural wash out, collapsing, induce fracture could indicate during drilling. A balance between stress concentration near rock strength is primary condition for a stability Thus,...

Wellbore stability are influenced by many complex factors, and there is no commonly used prediction method on wellbore stability until now. Use of an efficient decision making technique which can take into account several criteria in such conditions is necessary. Referring to traditional wellbore stability analyzing methods, the fuzzy comprehensive evaluation method of predicting wellbore stabi...

Wellbore cement, a procedural component of wellbore completion operations, primarily provides zonal isolation and mechanical support of the metal pipe (casing), and protects metal components from corrosive fluids. These are essential for uncompromised wellbore integrity. Cements can undergo multiple forms of failure, such as debonding at the cement/rock and cement/metal interfaces, fracturing, ...

Previously published field investigations and modeling studies have demonstrated the potential for sample bias associated with vertical wellbore flow in conventional monitoring wells constructed with long-screened intervals. This article builds on the existing body of literature by (1) demonstrating the utility of continuous (i.e., hourly measurements for ∼1 month) ambient wellbore flow monitor...