scholarly journals Dynamic Material Balance Method for Estimating Gas in Place of Abnormally High-Pressure Gas Reservoirs

Lithosphere ◽  
2021 ◽  
Vol 2021 (Special 1) ◽  
Author(s):  
Lixia Zhang ◽  
Yingxu He ◽  
Chunqiu Guo ◽  
Yang Yu
Keyword(s):  
High Pressure ◽  
Material Balance ◽  
Balance Method ◽  
Production Data ◽  
Reservoir Pressure ◽  
Material Balance Equation ◽  
Gas Reservoirs ◽  
Gas Reservoir ◽  
Material Balance Method ◽  
The Relationship

Abstract Determination of gas in place (GIP) is among the hotspot issues in the field of oil/gas reservoir engineering. The conventional material balance method and other relevant approaches have found widespread application in estimating GIP of a gas reservoir or well-controlled gas reserves, but they are normally not cost-effective. To calculate GIP of abnormally pressured gas reservoirs economically and accurately, this paper deduces an iteration method for GIP estimation from production data, taking into consideration the pore shrinkage of reservoir rock and the volume expansion of irreducible water, and presents a strategy for selecting an initial iteration value of GIP. The approach, termed DMBM-APGR (dynamic material balance method for abnormally pressured gas reservoirs) here, is based on two equations: dynamic material balance equation and static material balance equation for overpressured gas reservoirs. The former delineates the relationship between the quasipressure at bottomhole pressure and the one at average reservoir pressure, and the latter reflects the relationship between average reservoir pressure and cumulative gas production, both of which are rigidly demonstrated in the paper using the basic theory of gas flow through porous media and material balance principle. The method proves effective with several numerical cases under various production schedules and a field case under a variable rate/variable pressure schedule, and the calculation error of GIP does not go beyond 5% provided that the production data are credible. DMBM-APGR goes for gas reservoirs with abnormally high pressure as well as those with normal pressure in virtue of its strict theoretical foundation, which not only considers the compressibilities of rock and bound water, but also reckons with the changes in production rate and variations of gas properties as functions of pressure. The method may serve as a valuable and reliable tool in determining gas reserves.

scholarly journals Reserve evaluation of high pressure and ultra-high pressure reservoirs with power function material balance method

2019 ◽  
Vol 6 (5) ◽  
pp. 509-516 ◽  
Author(s):  
Hedong Sun ◽  
Hongyu Wang ◽  
Songbai Zhu ◽  
Haifeng Nie ◽  
Yang Liu ◽  
...  
Keyword(s):  
High Pressure ◽  
Power Function ◽  
Material Balance ◽  
Balance Method ◽  
Ultra High Pressure ◽  
Material Balance Method

Formation Pressure Calculation Based on Modified Flowing Material Balance Method

2014 ◽  
Vol 997 ◽  
pp. 868-872
Author(s):  
Quan Hua Huang ◽  
Huai Zhong Wen ◽  
Li Zhang ◽  
Tian Song
Keyword(s):  
Bottom Water ◽  
Material Balance ◽  
Reference Value ◽  
Balance Method ◽  
Formation Pressure ◽  
Gas Reservoir ◽  
Obvious Effect ◽  
Pressure Calculation ◽  
Flowing Material ◽  
Material Balance Method

Formation pressure is an important symbol of driving energy and the key problem of gas reservoir development. Therefore, the formation pressure’s evaluation is a very important work. Due to the invasion of edge-bottom water, using conventional "flow" material balance method to calculate the formation pressure is no longer applicable. According to the theory of reservoir pressure calculation based on flowing material balance method, we established a improved method to calculate the pressure of water drive gas reservoir and verified it by an example. The results show that: edge and bottom water intrusion has obvious effect on the calculation of formation pressure; after considering the influence of water drive, the formation pressure’s calculation results increased, as a consequence the formation pressure’s decreasing range reduced. This research’s result has important reference value for improving the precision of water drive gas reservoir’s formation pressure.

A Physics-Based Method To Forecast Production From Tight and Shale Petroleum Reservoirs by Use of Succession of Pseudosteady States

2015 ◽  
Vol 18 (04) ◽  
pp. 508-522 ◽  
Author(s):  
M. S. Shahamat ◽  
L.. Mattar ◽  
R.. Aguilera
Keyword(s):  
Balance Equation ◽  
Transient Flow ◽  
Material Balance ◽  
Petroleum Reservoirs ◽  
Flow Equation ◽  
Production Data ◽  
Material Balance Equation ◽  
Gas Reservoirs ◽  
Initial Flow ◽  
Shale Reservoirs

Summary Analysis of production data from tight and shale reservoirs requires the use of complex models for which the inputs are rarely known. The same objectives can also be achieved by knowing only the overall (bulk) characteristics of the reservoir, with no need for all the detailed and rarely known inputs. In this study, we introduce the concept of continuous succession of pseudosteady states as a method to perform the analysis of production data. It requires few input data yet is based on rigorous engineering concepts, which works during the transient- as well as the boundary-dominated-flow periods. This method consists of a combination of three simple and well-known equations: material balance, distance of investigation, and boundary-dominated flow. It is a form of a capacitance/resistance methodology in which the material-balance equation over the investigated region represents the capacitance and the boundary-dominated-flow equation represents the resistance. The flow regime in the region of investigation (the areal extent of which varies with time during transient flow) is assumed to be pseudosteady state. This region is depleted at a rate controlled by the material-balance equation. The initial flow rate and flowing pressure are used to define the resistance, and the distance of investigation defines the capacitance. The capacitance and resistance are then used in a stepwise procedure to calculate the depletion and the new rates or flowing pressures. The method was tested, for linear-flow geometry, against analytical solutions for liquids and numerical simulations for gas reservoirs, exhibiting both transient and boundary-dominated flow. Excellent agreement was obtained, thus corroborating the validity of the method developed in this study. Two practical examples are provided to demonstrate the applicability of the methodology to forecast production from tight and shale petroleum reservoirs. The proposed method is easy to implement in a spreadsheet application. It indicates that complex systems with complicated mathematical (e.g., Laplace space) solutions can be represented adequately by use of simple concepts. The approach offers a new insight into production analysis of tight and shale reservoirs, by use of familiar and easy-to-understand reservoir-engineering principles.

scholarly journals Flowing material balance method with adsorbed phase volumes for unconventional gas reservoirs

2019 ◽  
Vol 38 (2) ◽  
pp. 519-532
Author(s):  
Guofeng Han ◽  
Min Liu ◽  
Qi Li
Keyword(s):  
Coalbed Methane ◽  
Gas Adsorption ◽  
Material Balance ◽  
Balance Method ◽  
Gas Reservoirs ◽  
Unconventional Gas ◽  
Adsorbed Phase ◽  
Unconventional Gas Reservoirs ◽  
Flowing Material ◽  
Material Balance Method

This paper presents an improved flowing material balance method for unconventional gas reservoirs. The flowing material balance method is widely used to estimate geological reserves. However, in the case of the unconventional gas reservoirs, such as coalbed methane reservoirs and shale gas reservoirs, the conventional method is inapplicable due to the gas adsorption on the organic pore surface. In this study, a material balance equation considering adsorption phase volume is presented and a new total compressibility is defined. A pseudo-gas reservoir is simulated and the results were compared with the existing formulations. The results show that the proposed formulation can accurately get the geological reserves of adsorbed gas reservoirs. Furthermore, the results also show that the volume of the adsorbed phase has a significant influence on the analysis, and it can only be ignored when the Langmuir volume is negligible.

scholarly journals Integrated Reservoir Study to Optimize Gas Production of Water Drive Gas Reservoir Case Study: Lower Menggala Gas Field

INSIST ◽  
2018 ◽  
Vol 3 (2) ◽  
pp. 154
Author(s):  
Panca Suci Widiantoro ◽  
Astra Agus Pramana ◽  
Putu Suarsana ◽  
Anis N Utami
Keyword(s):  
Material Balance ◽  
Gas Production ◽  
Production Optimization ◽  
Balance Method ◽  
Water Production ◽  
Gas Reservoir ◽  
Gas Field ◽  
Production Analysis ◽  
Conventional Material ◽  
Material Balance Method

Production optimization in mature field water drive gas reservoir is not easy especially when water already breakthrough in producing wells. An integrated reservoir study is needed to get reliable strategy to optimize production of water drive gas reservoir.   This research presents the integrated reservoir study of Lower Menggala (LM) Gas Field which is located Central Sumatera Basin, Riau Province. LM had been produced since 1997, current RF are 55%, which is quite high for water drive gas reservoir. The current gas rate production is about 1.97 MMscfd with high water production around 4250 BWPD, consequently some of wells suffered liquid loading problem   This research comprises of well performance analysis, estimate OGIP, aquifer strength of the reservoir by using conventional material balance method and modern production analysis method then conduct dynamic reservoir simulation to identify the best strategy to optimize gas production. Economic analysis also be performed to guide in making decision which scenario will be selected. DST analysis on DC-01 well defined reservoir parameter, boundary and deliverability which are P*= 2520 psia, k= 229 mD, Total skin= 8, detected sealing fault with distance 175 m, and AOF 45 MMscfd. Conventional material balance method gave OGIP 22.7 BScf, aquifer strength 34 B/D/Psi, whereas modern production analysis estimated OGIP 22.35 BScf, aquifer strength 34 B/D/psi. Those two method shows  good consistency with OGIP  volumetric calculation with discrepancy OGIP value +/- 1%. Six (6) scenario of production optimization has been analyzed, the result shows that work over in two wells and drilling of  1 infill well (case 6) achieve gas recovery factor up to 75.2%, minimal water production and attractive economic result

scholarly journals Special features of tight gas reserves determination

2020 ◽  
pp. 19-28
Author(s):  
S. V. Krivulya ◽  
S. V. Matkivskyi ◽  
Ye. S. Bikman ◽  
O. R. Kondrat ◽  
O. V. Burachok
Keyword(s):  
Material Balance ◽  
Development Planning ◽  
Balance Method ◽  
Pressure Curve ◽  
Reservoir Pressure ◽  
Tight Gas ◽  
Initial Development ◽  
Field Development ◽  
Material Balance Method

Special features of tight gas reserves determination, based on material balance method, were characterized, since reliability of initial hydrocarbons in place determination plays important role in future field development planning, particularly on recovery rate, wells to be drilled, capital expenditures, surface facilities etc. Using the synthetic 3D model of gas reservoir, different development scenarios were evaluated according to the different spatial distribution patterns of petrophysical properties within the reservoir. Analyzing the obtained results, the authors fully confirmed an assumption made, that significant heterogeneity of reservoir properties makes a great impact on the shape of pseudo reservoir pressure curve vs cumulative gas produced and introduces significant errors into determination of initial gas in place. At the late stages of the development, the slope of P/z straight line changes, and this allows determination of much greater reserves’ volumes. Usage of pseudo reservoir pressure vs cumulative produced gas for determination of drained reserves in tight gas formation is especially risky, because the production data can indicate the true volumes of gas in place, only after the majority of the gas been produced. In most cases, the development period to acquire necessary data for correct volumes in place estimation exceeds the planning period. This factor introduces the significant error into future field development during the planning phase. Due to that, at the initial development stages, the error in drained volumes estimation can account for 50% out of true initial volumes in place. Based on conducted research, the potential error evaluation for tight gas reservoirs initial gas in place determination with decline pressure material balance method was performed. According to the results of computer simulation, the error can account for 25% from true initial gas in place in simulation model. This error significantly excesses the acceptable limits and can lead to wrong decisions in development planning

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