Drilling and Completion Waste Reutilization and Zero Discharge Technology Used in China Bohai Bay

2021 ◽  
Author(s):  
Kunjian Wang ◽  
Pengfei Liu ◽  
Xinxin Hou ◽  
Pan Wang ◽  
Pei Zhu ◽  
...  
Keyword(s):  
Solid Phase ◽  
Drilling Fluid ◽  
System Optimization ◽  
Field Application ◽  
Oil Field ◽  
Hole Drilling ◽  
Bohai Bay ◽  
Zero Discharge ◽  
Low Efficiency ◽  
Completion Fluids

Abstract With the increasingly stringent national environmental rules, waste produced in drilling and completion process is forbidden to be discharged into the Bohai Bay or reinjected into the formation. The current disposal method of drilling and completion waste in Bohai Oil field has some problems such as high cost, low efficiency and high HSE management and control risk. Faced with these problems, drilling and completion waste reutilization and zero discharge technology has been developed and applied in this region. In order to reutilize drilling and completion waste which include cuttings circulated from formation, wasted drilling and completion fluids, the following aspects are carried out: Firstly, drilling platform is upgraded to meet the zero discharge requirement: solid control system is modified, cuttings closed transfer system and cuttings treatment system are equipped on the platform to collect and dispose the waste. Meanwhile, recovery and disposal capacity to support different spud drilling are assessed: cuttings transport capacity is up to 15m3/h, which can meet the highest requirements of 12-1/4″ hole drilling when ROP is up to180m/h. Secondly, the well profile is downsized to reduce the production of cuttings, mud and other wastes from the root, which can also improve efficiency and yield cost. The field application shows that the amount of the waste has been reduced by 41.39%, 39.86% and 41.52% in first, second and third spud drilling, and average ROP is 35%, 28%, 42% higher than similar wells drilled before. Lastly, in drilling and completion fluids system optimization and reutilization aspects, environmentally friendly drilling and completion fluids with low solid content are developed. The experiment shows that the properties of the liquid phase after solid-liquid separation can be reused, and the solid phase with low water content is easy to pack and transport back to land. Drilling and completion waste reutilization and zero discharge technology introduced in this paper has been successfully applied in more than 40 wells, and the volume of waste drilling fluid is reduced by 80%, which is a trade-off between zero discharge and well construction cost. This technology can also be applied in other offshore oilfield which is inevitable as the environmental rules become more and more strict.

Stimulation of Wells Damaged by Barite Present in Filter Cake or Scale

SPE Journal ◽  
2021 ◽  
pp. 1-11
Author(s):  
Igor Ivanishin ◽  
Hisham A. Nasr-El-Din ◽  
Dmitriy Solnyshkin ◽  
Artem Klyubin
Keyword(s):  
High Temperature ◽  
Filter Cake ◽  
Ethylenediaminetetraacetic Acid ◽  
Solid Phase ◽  
Barium Carbonate ◽  
Process Analysis ◽  
Drilling Fluid ◽  
Field Application ◽  
X Ray ◽  
Dissolution Efficiency

Summary High-temperature (HT) deep carbonate reservoirs are typically drilled using barite (BaSO4) as a weighting material. Primary production in these tight reservoirs comes from the network of natural fractures, which are damaged by the invasion of mud filtrate during drilling operations. For this study, weighting material and drilling fluid were sampled at the same drillsite. X-ray diffraction (XRD) and X-ray fluorescence analyses confirmed the complex composition of the weighting material: 43.2 ± 3.8 wt% of BaSO4 and 47.8 ± 3.3 wt% of calcite (CaCO3); quartz and illite comprised the rest. The drilling fluid was used to form the filter cake in a high-pressure/high-temperature (HP/HT) filter-press apparatus at a temperature of 300°F and differential pressure of 500 psig. Compared with the weighting material, the filter cake contained less CaCO3, but more nondissolvable minerals, including quartz, illite, and kaolinite. This difference in mineral composition makes the filter cake more difficult to remove. Dissolution of laboratory-grade BaSO4, the field sample of the weighting material, and drilling-fluid filter cake were studied at 300°F and 1,000 to 1,050 psig using an autoclave equipped with a magnetic stirrer drive. Two independent techniques were used to investigate the dissolution process: analysis of the withdrawn-fluid samples using inductively coupled plasma-optical emission spectroscopy, and XRD analysis of the solid material left after the tests. The dissolution efficiency of commercial K5-diethylenetriaminepentaacetic acid (DTPA), two K4-ethylenediaminetetraacetic acid (EDTA), Na4-EDTA solutions, and two “barite dissolvers” of unknown composition was compared. K5-DTPA and K4-EDTA have similar efficiency in dissolving BaSO4 as a laboratory-grade chemical and a component of the calcite-containing weighting material. No pronounced dissolution-selectivity effect (i.e., preferential dissolution of CaCO3) was noted during the 6-hour dissolution tests with both solutions. Reported for the first time is the precipitation of barium carbonate (BaCO3) when a mixture of BaSO4 and CaCO3 is dissolved in DTPA or EDTA solutions. BaCO3 composes up to 30 wt% of the solid phase at the end of the 6-hour reaction, and can be dissolved during the field operations by 5 wt% hydrochloric acid. Being cheaper, K4-EDTA is the preferable stimulation fluid. Dilution of this chelate increases its dissolution efficiency. Compared with commonly recommended solutions of 0.5 to 0.6 M, a more dilute solution is suggested here for field application. The polymer breaker and K4-EDTA solution are incompatible; therefore, the damage should be removed in two stages if the polymer breaker is used.

Theoretical Basis for Prediction of Drilling Fluid Removal in Annuli

2017 ◽  
Author(s):  
Arild Saasen ◽  
Bjørnar Lund ◽  
Jan David Ytrehus
Keyword(s):  
Numerical Models ◽  
Drilling Fluid ◽  
Field Application ◽  
Displacement Efficiency ◽  
Fluid Removal ◽  
Pressure Losses ◽  
Variable Success ◽  
Variable Success Rate ◽  
Completion Fluids ◽  
Displacement Processes

Displacement processes are part of several drilling fluid operations. These operations include non-trivial items like changing from water based drilling fluid to oil based or opposite, casing cleaning operations, change to completion fluids or displacement operations during cementing. Among these operations, cementing is the most important and difficult because the scope is to create a permanent barrier and permanent zonal isolation in operations involving only limited volumes of fluids and slurries. Empirical guidelines have been implemented to improve displacement processes in wells. Analytical and numerical models are frequently used. The models seem to be efficient in predicting pressure losses. However, they seem to be incapable of accurately predict the displacement efficiency. Laboratory experimental results have been evaluated and have been scaled up to for field application with variable success rate. These difficulties are caused by the presence of too many length scales or other dimensional scales.

scholarly journals Construction and Application of Flocculation and Destability System of Biodrill-A Drilling Fluid in Bohai Oilfield

2021 ◽  
Vol 9 ◽  
Author(s):  
Yingwen Ma ◽  
Yuchen Zhang ◽  
Yang Liu ◽  
Ming Yue ◽  
Dongsen Wang ◽  
...  
Keyword(s):  
Ph Value ◽  
Solid Phase ◽  
Drilling Fluid ◽  
Bohai Bay ◽  
Clay Particles ◽  
Orthogonal Test Design ◽  
On Line ◽  
Fluid Separation ◽  
Flocculation Effect ◽  
Flocculation Time

To protect the marine ecological environment of Bohai Bay, the waste drilling fluid in Bohai oilfield have to be treated. In the light of the composition characteristics of Biodrill-A drilling fluid, the compounding method of the inorganic–organic flocculants was adopted to assist the flocculation and solid–fluid separation of Biodrill-A drilling fluid. Through the orthogonal test design, the main factors impacting the flocculation effect on Biodrill-A drilling fluid were found to the concentration of inorganic flocculant CaCl2 and the flocculation pH value. The optimal flocculation treatment was further obtained through single-factor optimization. Specifically, when the inorganic flocculant CaCl2 concentration was 0.9 w/v%, the organic flocculant concentration was 0.01 w/v%, the flocculation pH was 8, and the flocculation time was 7 min. Eventually, the final dewatering rate could reach 84.02%. In the optimized compound flocculants, the inorganic flocculant CaCl2 reduced the zeta potential of clay particles by electric neutralization to decrease the repulsion among particles, and the organic one could absorb and wrap the clay particles through bridging curling and electric neutralization after flocculation destabilization. Both inorganic and organic flocculants facilitated the large flocs and particles of clay particles. The field test showed that the inorganic–organic flocculants were suitable for the on-line flocculation treatment process based on centrifugal machine. The waste drilling fluid was reduced by 82%, and the water content of the separated solid phase was as low as 25.7%.

Application Study of Phase Inversion for Drilling Fluid in Well Lianhua 000-X2#

2012 ◽  
Vol 524-527 ◽  
pp. 1153-1156
Author(s):  
Li Yang ◽  
Yun Peng An ◽  
Nan Tian ◽  
Jun Ma ◽  
Jian Hua Yao
Keyword(s):  
Phase Inversion ◽  
Solid Phase ◽  
Drilling Fluid ◽  
Stability Loss ◽  
Field Application ◽  
Application Study ◽  
Well Control ◽  
Root Cause ◽  
Colloidal Properties ◽  
Water Based

In order to reduce the flow resistance of a water-based drilling fluid, emulsifiers tend to be added into the drilling fluid mixed with oil at the same time. However, inappropriate proportion or oil-based pipe free agent with low HLB value could easily trigger the phase inversion of the drilling fluid, causing its stability loss or even water–solid separation. Therefore, starting from the root cause of the phase inversion, the surfactivity of solid-phase materials in the drilling fluid was changed from hydrophobicity to hydrophilicity by adding surfactants with high HLB value. Then its colloidal properties were reestablished by combining alkali diluting agent, and the drilling fluid with phase inversion of well Lianhua 000-X2# was treated indoors. The results of the field application in the well show that high-HLB surfactant can solve the phase inversion of a water-based drilling fluid properly, and that barite sedimentation and well control problem, caused by the phase inversion of the water-based drilling fluid with high-density, can be avoided.

scholarly journals Injection-production optimization of carbonate reservoir based on an inter-well connectivity model

2021 ◽  
pp. 014459872199465
Author(s):  
Yuhui Zhou ◽  
Sheng Lei ◽  
Xuebiao Du ◽  
Shichang Ju ◽  
Wei Li
Keyword(s):  
History Matching ◽  
Water Injection ◽  
Field Application ◽  
Carbonate Reservoir ◽  
Production Optimization ◽  
Oil Field ◽  
Carbonate Reservoirs ◽  
Utilization Rate ◽  
Production Volume ◽  
Connectivity Model

Carbonate reservoirs are highly heterogeneous. During waterflooding stage, the channeling phenomenon of displacing fluid in high-permeability layers easily leads to early water breakthrough and high water-cut with low recovery rate. To quantitatively characterize the inter-well connectivity parameters (including conductivity and connected volume), we developed an inter-well connectivity model based on the principle of inter-well connectivity and the geological data and development performance of carbonate reservoirs. Thus, the planar water injection allocation factors and water injection utilization rate of different layers can be obtained. In addition, when the proposed model is integrated with automatic history matching method and production optimization algorithm, the real-time oil and water production can be optimized and predicted. Field application demonstrates that adjusting injection parameters based on the model outputs results in a 1.5% increase in annual oil production, which offers significant guidance for the efficient development of similar oil reservoirs. In this study, the connectivity method was applied to multi-layer real reservoirs for the first time, and the injection and production volume of injection-production wells were repeatedly updated based on multiple iterations of water injection efficiency. The correctness of the method was verified by conceptual calculations and then applied to real reservoirs. So that the oil field can increase production in a short time, and has good application value.

Downhole CO2 partial pressure calculation and tubing material selection – a case study of an offshore oil field in the South China Sea

2016 ◽  
Vol 63 (5) ◽  
pp. 414-420 ◽  
Author(s):  
Wei Yan ◽  
Yong Xiang ◽  
Wenliang Li ◽  
Jingen Deng
Keyword(s):  
Partial Pressure ◽  
Pressure Profile ◽  
Field Application ◽  
Separation Process ◽  
Oil Field ◽  
Oil Well ◽  
Content Type ◽  
Calculating Method ◽  
Oil Gas

Purpose This paper aims to establish the downhole CO2 partial pressure profile calculating method and then to make an economical oil country tubular goods (OCTG) anti-corrosion design. CO2 partial pressure is the most important parameter to the oil and gas corrosion research for these wells which contain sweet gas of CO2. However, till now, there has not been a recognized method for calculating this important value. Especially in oil well, CO2 partial pressure calculation seems more complicated. Based on Dolton partial pressure law and oil gas separation process, CO2 partial pressure profile calculating method in oil well is proposed. A case study was presented according to the new method, and two kinds of corrosion environment were determined. An experimental research was conducted on N80, 3Cr-L80 and 13Cr-L80 material. Based on the test results, 3Cr-L80 was recommended for downhole tubing. Combined with the field application practice, 3Cr-L80 was proved as a safety and economy anti-corrosion tubing material in this oil field. A proper corrosion parameter (mainly refers to CO2 partial pressure and temperature) can ensure a safety and economy downhole tubing anti-corrosion design. Design/methodology/approach Based on Dolton partial pressure law and oil gas separation process, CO2 partial pressure profile calculating method in oil well is proposed. An experimental research was conducted on N80, 3Cr-L80 and 13Cr-L80 material. A field application practice was used. Findings It is necessary to calculate the CO2 partial pressure properly to ensure a safety and economy downhole tubing (or casing) anti-corrosion design. Originality/value The gas and oil separation theory and corrosion theory are combined together to give a useful method in downhole tubing anti-corrosion design method.

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