Papers by Keyword: Deep Well

Abstract: With the exploitation of deep well, ultra-deep well, thermal recovery Well and Geothermal Well, the temperature of tubing and casing is increasing constantly. The influence degree of temperature on tubing and casing material performance has attracted much attention in the design of tubular strings. The experimental study on the yield strength and tensile strength of tubular materials with temperature change is carried out, which includes C110, 140ksi, P110 and S13Cr110. In this paper, the yield strength correction coefficient of tubular material is defined, and the material performance model of different steel grade tubular material with temperature change is established. The paper describes the influence of underground high temperature on the design of tubular strings and shows that the yield strength of tubular material will decrease under high temperature. This directly affects the safety parameter of tubing and casing design, and greatly impact on the safety reliability and service life of the tubular strings. This paper points out the defects which exist in the current API formulas, when calculating the force of the tubular string. It is suggested that the yield strength at high temperature should be used as the design basis for deep well and ultra-deep well when the underground temperature is high. The results can be used to guide the design and check of tubular strings under high temperature and high-pressure gas well.Keywords:deep and ultra-deep well; special performance tubing and casing; high temperature; yield strength; tubular strings integrity;OCTG

Abstract: Based on the deep soft rock creep mechanism, according to the physical characteristics of bauxitic mudstone in ingate at the level of -1015 m of Kong Zhuang colliery, we solved the technical difficult problem of choosing anchor points of soft rock supporting roadway in ingate. Using high strength and low relaxation steel strand to reinforce by crossed anchor, in combination with the depth hole grouting technology, improve pressure-bearing capacity of wall rock in the ingate, safe passage and drainage pipe area. We analyze the stress distribution characteristics of rock mass, contrasting on the stress distribution at the end of partially grouted bolt and the rock mass. Practice shows that crossed anchor rock mass has triaxial compression over all, the bunch body has a single structure, and it is easily to be analyzed. We not only control the roof settling in the area of ingate is, but also solve the floor heave problem in safe passage and drainage pipe area.

Abstract: Petroleum industry is focusing on high-pressure and high-temperature (HPHT) reservoir. The major problem facing to HPHT reservoir is to generate enough bottomhole pressure without exceeding the limitations of equipment on the ground. In order to overcome these problems, weighted fracturing fluid system has been developed whose density can reach up to 1.50 g/cm3. This paper summarizes a study on formulating sodium bromide and sodium chloride as a combined weighted agent and a delayed crosslinked fracturing fluid system which is to cater the fluid and treatment guidelines for the fracturing application. Extensive studies were also conducted to determine temperature stability and anti-shear properties and gel broken.

Abstract: To estimate the effect of deep large section Shaft Face Grouting for water block, the mathematical model is obtained according to the seepage theory. The numerical model for calculation is established by the program ABAQUS. The laws of change of pore water pressure, the effect area of dewatering, the velocity of seepage, water inflow of shaft working face before and after grouting is obtained by numerical simulation. It is shown that the grouting can effectively plug water channel of cracked surrounding rock, and prevent the pore water pressure lowering range to be larger. The working face seepage flow velocity was significantly reduced. The water inflow is decreased significantly. The safety of the shaft construction and the stability structure of shaft lining and upper strata are ensured by grouting. The numbers of grout stop and grouting construction can be largely reduced. The economic benefit is obvious. The scientific reference is provided for deep large section Shaft Face Grouting for water block.

Abstract: In real life, deep well trapping accidents of people frequently occur，but no appropriate and effective rescue equipment is available. After site investigation and analysis, we hereby design a sort of remote control deep well rescue machine, in which the components are free to remove，the length can be freely adjusted according to the depth of wells. The bottom of the device is provided with mechanical hands and chassis with airbags. By controlling the robot with remote control technology, the device solves the problem that the rescue workers can not perform direct rescue on the victims due to the small width of the well mouth. A camera is installed at the lower part of the device, which enables the rescuers to accurately observe the underground situation, thereby solving the problem of being unable to accurately locate the trapped people with human eyes due to the smallness of the well mouth and insufficient light.

Abstract: In the low-pressure pulse and cavitation jet compound drilling technology, pulse low-pressure and cavitation jet generator is installed on bit, water jet modulated by generator can generate pulse low-pressure, which will alternate rock mechanics, decrease rock breaking strength, increase rock-breaking efficiency. And cavitation jet generated can increase hydraulic power downhole. The results show that low-pressure pulse and cavitation jet generator has been run well from 5349m to 6162m for 129.36h-136.63h in TK1090 well, increasing drilling speed 40.6%～85.1%. The low-pressure pulse and cavitation jet compound drilling technology can increase drill speed and be deployment in deep well drilling.