Jidong Oilfield Research Articles

Characteristics of hydrocarbon hydroxylase genes in a thermophilic aerobic biological system treating oily produced wastewater.

Alkane and aromatic hydroxylase genes in a full-scale aerobic system treating oily produced wastewater under thermophilic condition (45-50 °C) in the Jidong oilfield, China, were investigated using clone library and quantitative polymerase chain reaction methods. Rather than the normally encountered integral-membrane non-haem iron monooxygenase (alkB) genes, only CYP153-type P450 hydroxylase genes were detected for the alkane activation, indicating that the terminal oxidation of alkanes might be mainly mediated by the CYP153-type alkane hydroxylases in the thermophilic aerobic process. Most of the obtained CYP153 gene clones showed distant homology with the reference sequences, which might represent novel alkane hydroxylases. For the aromatic activation, the polycyclic aromatic hydrocarbon-ring hydroxylating dioxygenase (PAH-RHD) gene was derived from Gram-negative PAH-degraders belonging to the Burkholderiales order, with a 0.72% relative abundance of PAH-RHD gene to 16S rRNA gene. This was consistent with the result of 16S rRNA gene analysis, indicating that Burkholderiales bacteria might play a key role in the full-scale process of thermophilic hydrocarbon degradation.

Carbon Dioxide Flooding Technology Research and Field Test in Liuzan North Block

The fault roots of Liuzan north block in Jidong oilfield of China have been long-term explored by solution gas drive. Recently, oil production declined rapidly because of shortage of formation energy and needing high water injection pressure. Carbon dioxide injection pressure is found to be generally low, and CO 2 has good solubility in crude oil to supply formation energy and achieve high oil recovery efficiency. In this work, a pilot program of CO 2 EOR technology was carried out. The slim tube test results showed that the minimal miscible pressure of Liuzan north block was 28.28 MPa. The injection parameters were optimized by numerical simulation method: the injection method was continuous, the slug size was 0.2 HCPV and the EOR efficiency was 7.23%. After two months of gas injection field test, the formation pressure of two gas injectors just increased by 14.02 MPa and 2.98 MPa, respectively, indicating that carbon dioxide could supply the formation energy effectively. 16 months after gas injection, the CO 2 injection amount was 14640 t, and the oil increment was 16424 t. The present work demonstrates the potential applicability of CO 2 flooding technology from high water injection reservoirs.

Water and Sand Control Technology Successfully Applied in Jidong Oilfield: A Case Study

In order to solve the growing water production problem of screen pipe completed horizontal wells in unconsolidated sandstone reservoirs, water and sand control screen pipe was developed. By combining swellable packers, installing different sized nozzles, and assorting corollary tools, a water and sand control completion string was formed and then field tests were carried out. The field application shows that water cut of water and sand control screen pipe completed horizontal wells raises much slower compared to conventional screen pipe completed horizontal wells.

Application of HAZOP Method in the Design of Shallow Water Catheter Frame Platform

HAZOP (Hazard and Operability Study) is a system analysis method used to identify design defects and dangerousness and operability of process, , which has been widely used in the oil industry at home and abroad. In this paper the basic principle and analysis process of HAZOP analysis method were detailedly introduced. Taken the HAZOP practical application of offshore jacket platform in Jidong Oilfield for example, the defects which can lead the security and operation problems during the process of equipments design and operation were systematically identified. Combined with analyses of the achievements of this practical application, the advantages of the implementation of HAZOP method are concluded such as effectively reducing engineering design defects and safety problem of operation process; improving safe reliability of process system.

Study on the HSE Management at Construction Site of Oil and Gas Processing Area

Abstract With the constant development and oil production increment of Jidong Oilfield, higher requests for oil and gas processing technology and equipment are put forward. Large-scale technical renovations have been implemented in oil and gas processing areas every year, in order to offer better services to the production process. But in the process of transformation a multitude of problems are exposed, which are the important causes of the accidents. In this paper the above problems were analyzed and researched, the basic reasons were identified, the improvement measures were put forward, the level of HSE management was improved and all kinds of potential safety hazards were eliminated. It is shown that through more than two years HSE management at oil and gas processing plant site, the rate of safety hazards elimination has been enhanced while the rate of accident at construction site has been reduced obviously.

Coupling Law Research of Single Phase Stress Field / Seepage Field in Reservoir Deformation Medium

On the basis of summarizing the predecessors' achievements，according to the basic theory of rock mechanics, fluid mechanics in porous medium, geologic mechanics, calculated mechanics and fluid-solid coupling seepage, a mathematical and numerical model of seepage field and stress field coupling is developed in porous medium and the LiuNan blocks of JiDong oilfield wells.based area single phase Stress Field / Seepage Field in solving with the method of finite element software ANSYS, Contrast analysis of LiuNan blocks Coupling around of Field / Seepage Field is the change of average stress and total displacement. As can be seen from Table 3, after coupling the value of average stress and total displacement are greater than before coupling.So from figure 2 know than it is important meaning for used to solve practical engineering problems.

TIDAL DYNAMIC GEOMORPHOLOGY IN NANPU AREA OF BOHAI BAY

With the development of the Jidong oilfield,three large artificial islands have been planned in the coastal water around the Nanpu area in recent years.To well understand the character of dynamic geomorphology of the area is significant for the construction of artificial islands.Using the data of measured tide and related currents offshore,in combination with the data from side-scan sonar and offshore sampling,the authors studied the tidal dynamic geomorphology pattern around the three planned artificial islands,and discussed the possible migration of nearby sand ridges,and its impact on construction of artificial islands.The impact of the construction to the tidal dynamic system is also predicted.

The Finite Element Analysis of Coupling Law of Single Phase Stress Field / Seepage Field in Permeable Stratum Medium

The research of reservoir fluid-solid coupling theory is hot issues in home or foreign recently, In oil, civil, environment and geology, mining and other fields with a wide application. On the basis of summarizing the predecessors' achievements，according to the basic theory of rock mechanics, fluid mechanics in porous medium, geologic mechanics, calculated mechanics and fluid-solid coupling seepage, a mathematical and numerical model of seepage field and stress field coupling is developed in porous medium and the LiuNan blocks of JiDong oilfield wells.based area single phase Stress Field / Seepage Field in solving with the method of finite element software ANSYS, Contrast analysis of LiuNan blocks Coupling around of Field / Seepage Field is the change of average stress and total displacement. As can be seen from Table 3, after coupling the value of average stress and total displacement are greater than before coupling.The results show than it is important meaning for used to solve practical engineering problems.

Practices and expectation of high-density seismic exploration technology in CNPC

Abstract China National Petroleum Corporation (CNPC) carried out 2D high-density seismic surveys in western and eastern China from 2003 and 3D high-density seismic surveys in Tazhong area of Tarim Basin, Northwest margin of Junggar Basin, Qiulin Oilfield of Tuha Basin, Songliao Basin, Huanxiling of Liaohe Oilfield, and beach area of Jidong Oilfield from 2006. The total coverage area of 3D high-density seismic surveys was 654 km 2 of which 100 km 2 was 3D and 3C digital seismic. The surveys achieved preferable results under the high-coverage data acquisition and new data processing technologies. Technical advancement makes it possible to apply large-scale high-density seismic surveys. We can use the imaging trace density to scale whether the geometry is high-density seismic sampling in order to meet the requirement of prestack data processing. In the principle of spatial sampling with “sufficiency, equality, symmetry, and continuity”, and in combination with the geological targets and the problems to be solved, the integrated performance of acquisition, processing, and interpretation shall be the orientation of high-density seismic technologies in CNPC in future.

Research on Identification and Screen of Microbial Desulfurization Strains for Petroleum

The oil-contaminated soil sample was acquired from Shengli Oilfield and Jidong Oilfield and cultured with enrichment technology. Then 21 desulfurization strains were separated from the sample, from which a high efficiency desulfurization strain TV9704 was selected. The strain could neither grow with n-dodecane, n-hexadecane, liquid paraffin, naphthalene or diesel as a carbon source and energy source, nor obviously reduce oil combustion value. It could use thiophene or dibenzothiophene (DBT) as the sole sulfur source. In the experiment, the concentrations of thiophene and DBT were measured by UV spectrophotometer. After being cultured in the culture medium with an initial concentration of 63.2 mmol/L respectively for 48 h and 144 h, the degradation rates of the strain TV9704 on thiophene were 39.0% and 63.8%; the DBT with an initial concentration of 2.7 mmol/L was degraded by 1.46 mmol/L after cultured for 72 h. When sodium acetate and glycerol were chosen as carbon source, the ethanol could enhance the degradation rate of TV9704 on DBT significantly. Strain TV9704 was identified by China Industrial Culture Collection Center (CICC) as a Bacillus sp., Gram-positive, obligate aerobic, which forms a circular orange colony on the nutrition gravy plate. The 16SrDNA gene sequencing test and analysis was carried out on strain TV9704, finding that its homologies with the most similar species Bacillus aquimaris and Bacillus marisflavi were 99.2% and 98.2% respectively, but a larger difference existed between their cell morphological characteristics and physiological and biochemical characteristics, therefore strain TV9704 may be a new species because it was impossible to be categorized to any population.

Screenless Frac-Pack Completions: Case Studies From Jidong Field, China

This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper SPE 108909, "Screenless Frac-Pack Completions - Case Studies From Jidong Field, China," by Chang Xue Jun, SPE and Chen Ren Bao, PetroChina Jidong Oilfield, and Wirdansyah Lubis, Deng Hui, and Philip Nguyen, SPE, Halliburton, originally prepared for the 2007 SPE Asia Pacific Oil and Gas Conference and Exhibition, Jakarta, 30 October-1 November. The paper has not been peer reviewed. With careful planning, a screenless frac-pack treatment provides an effective method for controlling flowback of proppant and formation sand to maintain well production without work-overs caused by solid-particulate production. Properly coating with optimal liquid-resin-system (LRS) concentration and curing, LRS-coated proppant will transform into a high-strength, permeable mass to withstand high drawdown and the effect of stress/strain cycles during well operations. Screenless frac pack is an economical- and viable-completion method for wells with marginal reserves. Introduction The case studies discussed in the full-length paper are oil wells operated by PetroChina in the Jidong oil field. These wells generally have high-permeability unconsolidated sand and high water saturation. Over the past several years, the operator has applied high-rate water-pack completions to control production of formation sand and fines in these wells. Since being drilled, each of these wells has been completed at least twice using a high-rate water-pack method. The objective of this completion technique was to create a tight proppant pack in the annulus between perforated casing and the sand screen, with the attempt to squeeze as much proppant as possible out into the formation to control migration of formation sand and fines, bypassing near-wellbore damage, and to obtain a low skin factor. The production results, however, indicated that this completion method was not as successful as planned. Even after being completed with premium screens, these wells continued to produce formation sand, resulting in decreased production and plugging of electrical submersible pumps, requiring frequent workovers and downtime. The screens often became plugged with formation sand and fines. Sand production prevented the operator from increasing well production to desired levels. The operator also tried flexible-proppant technology in one well, as a field trial, by mixing deformable particulates as part of the proppant to help lock the proppant in place. However, proppant and formation sand continued to be produced as a result of insufficient cohesion provided by the deformable particulates and their inability to withstand high surges of production fluids. In addition to the disappointing performance of these completions, the frequency of workovers required to clean out proppant and formation sand in these wells averaged once every 2 to 3 months. As a result, the operator considered field trials of screenless frac-pack completions using a tip-screenout design and a newly developed curable resin for controlling flowback of proppant and formation sand. These completions were performed in two campaigns during the second quarter of 2006 and the first quarter of 2007, respectively.

Oil-gas exploration potential for above-source plays in Nanpu sag

Abstract The above-source plays in the Nanpu Sag, including E 3 d 1 , Ng and Nm, are the main contribution to the present reserves and production increase in the PetroChina Jidong Oilfield Company. The reservoir-forming mechanism for the above-source plays is studied according to the analysis of structure and reservoirs, the determination of reservoir-forming period and the modeling of reservoir-forming processes. There are two stages of oil infilling: early Nm and late Nm. The key factor for the above-source plays is the oil-source fault along which oil and gas migrate upward under the high residual pressure difference between source rock and reservoirs providing sufficient oil source in forming reservoirs. The hydrocarbon accumulation in the above-source play is controlled by the oil-source fault and the related structural traps. The conjugate shear belt which has huge oil and gas potential under compression and torsion stresses is an important exploration target.

Co-variations of bacterial composition and catabolic genes related to PAH degradation in a produced water treatment system consisting of successive anoxic and aerobic units

This paper reports on the investigation of concentration levels of PAHs, community structure, as well as the abundance of PAH-related catabolic genes including upper-pathway dioxygenase genes (nahAc and phnAc) and down-pathway catechol dioxygenase genes (C12O and C23O) in a successive anoxic and aerobic treatment of produced water from the Jidong Oilfield, China. 93% of total PAHs were removed, almost equally contributed by the anoxic and aerobic units. However, PAHs of more than 3 benzene rings remained almost unchanged. The signals for phnAc and C12O were undetectable in this biological system, whereas the existence of nahAc and C23O was confirmed in the system and the copies of the two genes in the aerobic tank were 2 or 3 orders higher than those in the influent water sample. The different behavior of C23O demonstrated that mineralization of PAHs might mainly occur in the aerobic unit. The existence of nahAc and C23O genes in the influent and the high similarity of genotype between the influent and the two sludge samples suggested that bacteria existing in the influent contributed to PAH removal and bacteria harboring PAH catabolic genes were enriched in the sludge.