黄海海域前新生代残留盆地综合地质地球物理研究

China’s annual oil import volume has been increasing in recent years, but the oil price in the international market fluctuates and poses a severe threat to China’s economic development and national security. Therefore, it is of great importance to study the gas and oil exploration of Pre-Cenozoic Residual Basins in Yellow Sea. Yellow Sea has widespread and thick Mesozoic and Paleozoic strata that contain multilayer source rock. Hence, Yellow Sea Mesozoic and Paleozoic strata have good conditions of forming Pre-Cenozoic hydrocarbon reservoirs. Pre-Cenozoic Residual Basins are usually buried deep and then transformed many times in its long evolutional history. These characteristics make it difficult to apply a single method in exploring Pre-Cenozoic Residual Basins. On the other hand, it is highly effective to solve key problems of gas and oil exploration of Pre-Cenozoic Residual Basins in Yellow Sea by using integrated geological and geophysical methods which make full use of the advantages of various exploring techniques. Based on the principle of “the region controls the local; the deep restricts the shallow,” this study focuses on Pre-Cenozoic Residual Basins in Yellow Sea to describe the structure frame of its distribution, with gravity, magnetic, seismic, drill-hole and geological data and previous research findings. In addition, the distribution characteristics of Pre-Cenozoic Residual Basins in Yellow Sea are also analyzed. This paper explores the characteristics of error between gravity forward with constant density and gravity forward with variable density through the study on 2-D and 3-D gravity forward in frequency domain. The result shows that there is a linear relationship between error and depth of 2-D geological model but there is a nonlinear relationship between error and depth of 3-D geological model. The error can be removed according to its linear characteristics or statistical nature of nonlinear characteristics. There is also error between gravity inversion with constant density and gravity inversion with variable density due to variable density and edge-effect. Since there are not noticeable rules between the error and the two causes as variable density and edge-effect, this study adopts gravity inversion with variable density and methods to eliminate the edge-effect in basement inversion to improve inversion accuracy. Based on the study on the rock physical properties and strata distribution of Yellow Sea and adjacent regions, this study finds that there is a big density contrast between Cretaceous-Jurassic strata and their substratum. The magnetic basement of south Yellow Sea is regarded as top of Archeozoic-Proterozoic early strata, and there are double magnetic basements in north Yellow Sea. Gravity and magnetic data are used to inverse the gravity basement and magnetic basement of Yellow Sea, with seismic and drill-hole data as constrains. According to data of gravity and magnetic basement distribution, the depth of Cenozoic strata and previous research findings, this paper calculates the thickness of the Mesozoic and Pre-Mesozoic Residual Basins, draws the distribution outline of Pre-Cenozoic Residual Basins in Yellow Sea, and analyzes its macro-distribution characteristics. Gravity inversion is applied on a typical geological profile in Yellow Sea to analyze the characteristics of its fractures and magnetic basements. The characteristics of Pre-Cenozoic Residual Basins distribution outline in Yellow Sea and the fractures and magnetic basements of its typical profile shown by profile inversion provides new geophysical evidence for these structure views such as “the South Yellow Sea and the North Yellow Sea belong to different structural units” and “Sino-Korea and Yangtze blocks combine along Yellow Sea East Fractured Zone in Yellow Sea”.

A Research on New Method of Transportation Technics for Heavy Oil and Practice in Oil Field

介绍一种可应用于高粘度稠油管输的新工艺。即用自行研制的蒸汽引射器采用无界引射方式,将蒸汽直接注入到输油管道中,利用蒸汽释放的热量提高稠油温度降低粘度,从而达到降低稠油输送压降的目的,它比间接加热输送工艺所用的蒸汽量或耗煤量大大减少。方法在辽河油田输油管线上进行了工业现场试验,取得了很好的效果。

Experimental study and simulation principles of an oil-gas multiphase transportation system

Presented is an experimental study on the performance of an oil-gas multiphase transportation system, especially on the multiphase flow patterns, multiphase pumping and multiphase metering of the system. A dynamic simulation analysis is conducted to deduce simulation parameters of the system and similarity criteria under simplified conditions are obtained. The reliability and feasibility of two-phase flow experiment with oil and natural gas simulated by water and air are discussed by using the similarity criteria.

Simulations of oil spread on a water surface

Numerical simulation of an oil slick spreading on still and wavy surfaces is described in this paper. The so-called sigma transformation is used to transform the time-varying physical domain into a fixed calculation domain for the water wave motions and, at the same time, the continuity equation is changed into an advection equation of wave elevation. This evolution equation is discretized by the forward time and central space scheme, and the momentum equations by the projection method. A damping zone is set up in front of the outlet boundary coupled with a Sommerfeld-Orlanski condition at that boundary to minimize the wave reflection. The equations for the oil slick are depth-averaged and coupled with the water motions when solving numerically. As examples, sinusoidal and solitary water waves, the oil spread on a smooth plane and on still and wavy water surfaces are calculated to examine the accuracy of simulating water waves by Navier-Stokes equations, the effect of damping zone on wave reflection and the precise structures of oil spread on waves.

Numerical Simulation of Particle Separation in An Oil-Sand Separator

The gathering systems of crude oil are greatly endangered by the fine sand and soil in oil. Up to now , how to separate sand from the viscid oil is still a technical problem for oil production home or abroad. Recently , Institute of Mechanics in Chinese Academy of Sciences has developed a new type of oil-sand separator , which has been applied successfully in oil field in situ. In this paper, the numerical method of vortex-stream function is used to predict the liquid-solid separating course and the efficiency for this oil-sand separator. Results show that the viscosity and particle diameter have much influence on the particle motion. The calculating separating efficiency is compared with that of experiment and indicates that this method can be used to model the complex two-phase flow in the separator.

Mechanics of a grip system of three-key-board hydraulic tongs developed for offshore oil pipe lines

This paper carries out the analysis of mechanics of a grip system of three-key-board hydraulic tongs developed for offshore oil pipe lines which has been successfully used in oil fields in China. The main improvement of this system is that a lever frame structure is used in the structural design, which reduces greatly the stresses of the major components of the oil pipe tongs. Theoretical analysis and numerical calculation based on thirteen basic equations developed Show that the teeth board of the tongs is not easy to slip as frequently happens to other systems and is of higher reliability.

Oil-Water Two-Phase Flow Inside T-Junction

The oil/water two-phase flow inside T-junctions was numerically simulated with a 3-D two-fluid model, and the turbulence was described using the mixture k - epsilon model. Some experiments of oil/water flow inside a single T-junction were conducted in the laboratory. The results show that the separating performance of T-junction largely depends oil the inlet volumetric fraction and flow patterns. A reasonable agreement is reached between the numerical simulation and the experiments for both the oil fraction distribution and the separation efficiency.

Experimental Investigation On The Slip Between Oil And Water In Horizontal Pipes

This work is devoted to study of the slip phenomenon between phases in water-oil two-phase flow in horizontal pipes. The emphasis is placed on the effects of input fluids flow rates, pipe diameter and viscosities of oil phase on the slip. Experiments were conducted to measure the holdup in two horizontal pipes with 0.05 m diameter and 0.025 m diameter, respectively, using two different viscosities of white oil and tap water as liquid phases. Results showed that the ratios of in situ oil to water velocity at the pipe of small diameter are higher than those at the pipe of big diameter when having same input flow rates. At low input water flow rate, there is a large deviation on the holdup between two flow systems with different oil viscosities and the deviation becomes gradually smaller with further increased input water flow rate. (C) 2008 Elsevier Inc. All rights reserved.

Experimental Investigation On The Holdup Distribution Of Oil-Water Two-Phase Flow In Horizontal Parallel Tubes

An experimental investigation was conducted to study the holdup distribution of oil and water two-phase flow in two parallel tubes with unequal tube diameter. Tests were performed using white oil (of viscosity 52 mPa s and density 860 kg/m(3)) and tap water as liquid phases at room temperature and atmospheric outlet pressure. Measurements were taken of water flow rates from 0.5 to 12.5 m(3)/h and input oil volume fractions from 3 to 94 %. Results showed that there were different flow pattern maps between the run and bypass tubes when oil-water two-phase flow is found in the parallel tubes. At low input fluid flow rates, a large deviation could be found on the average oil holdup between the bypass and the run tubes. However, with increased input oil fraction at constant water flow rate, the holdup at the bypass tube became close to that at the run tube. Furthermore, experimental data showed that there was no significant variation in flow pattern and holdup between the run and main tubes. In order to calculate the holdup in the form of segregated flow, the drift flux model has been used here.

A coupled model for multiphase fluid flow and sedimentation deformation in oil reservoir and its numerical simulation

A mathematical model for coupled multiphase fluid flow and sedimentation deformation is developed based on fluid-solid interaction mechanism. A finite difference-finite element numerical approach is presented. The results of an example show that the fluid-solid coupled effect has great influence on multiphase fluid flow and reservoir recovery performances, and the coupled model has practical significance for oilfield development.

Study on the Performance of a Compact Compound Oil/Gas/Water Separator for Offshore Oil Industry

High-efficiency separation of the oil/gas/water mixtures is a significant issue in offshore oil industry. To reduce the total cost by means of reduction in weight and space compared with conventional separators, a novel compact compound oil/gas/water separator is developed. The research works on oil-gas-water separation by compound separating techniques is described in this paper. The innovative separator is a gravity settling tank with helical pipes within and T-shaped pipes outside. Both experiments and numerical simulations are presented to study the separating performance and efficiency of the helical pipes, which are the main part of the separator.

Effect of Pipe Diameter on Flow Pattern Transition in Vertical Oil Water Flows

This paper investiges the effect of pipe diameter on flow pattern transition boundary in oil water vertical flows, and proposes a model to determine the maximum inner diameter (D_{infty s}) of a pipe in which the slug flow would not occur When pipe inner diameter D>D_{infty s}, only bubble flow exists, while D

Multiphase Flow Measurement in the Offshore Oil Industry

In recent years, considerable research has been conducted into the development of a three-phase flowmeter suitable for use in an offshore environment, and oil/gas/water three-phase metering becomes an important aspect in multiphase flow measurement. This paper discusses the importance of three-phase flow measurement in offshore oil industry, describes the current development in this area, and points out the principal strategies which may be used to meter three-phase flow.